*BEGIN GRAPHICS VERSION=442/420 ENCODING=7BIT ** "Creator" brian ** "Creation Date" Sat May 4 18:52:16 2002 ** "Creation Version" 4.42 (1021.500) ** "Revisor" brian ** "Last Modified" Mon Mar 1 16:26:16 2004 ** "Last Modified Version" 4.42 (1021.500) COLORMAP <"Transparent" 0 0 0 0 0 1> <"Black" 0 0 0 0 255 0> <"White" 0 0 0 0 0 0> <"Grey 95" 0 0 0 0 13 0> <"Grey 87" 0 0 0 0 33 0> <"Grey 75" 0 0 0 0 64 0> <"Grey 50" 0 0 0 0 128 0> <"Red" 0 0 255 255 0 0> <"Red 95" 0 13 255 255 0 0> <"Red 87" 0 33 255 255 0 0> <"Red 75" 0 64 255 255 0 0> <"Red 50" 0 128 255 255 0 0> <"Green" 0 255 0 255 0 0> <"Green 95" 0 255 13 255 0 0> <"Green 87" 0 255 33 255 0 0> <"Green 75" 0 255 64 255 0 0> <"Green 50" 0 255 128 255 0 0> <"Blue" 0 255 255 0 0 0> <"Blue 95" 0 255 255 13 0 0> <"Blue 87" 0 255 255 33 0 0> <"Blue 75" 0 255 255 64 0 0> <"Blue 50" 0 255 255 128 0 0> <"Yellow" 0 0 0 255 0 0> <"Yellow 95" 0 0 0 255 13 0> <"Yellow 87" 0 0 0 255 33 0> <"Yellow 75" 0 0 0 255 64 0> <"Yellow 50" 0 0 0 255 128 0> <"Magenta" 0 0 255 0 0 0> <"Magenta 95" 0 0 255 0 13 0> <"Magenta 87" 0 0 255 0 33 0> <"Magenta 75" 0 0 255 0 64 0> <"Magenta 50" 0 0 255 0 128 0> <"Cyan" 0 255 0 0 0 0> <"Cyan 95" 0 255 0 0 13 0> <"Cyan 87" 0 255 0 0 33 0> <"Cyan 75" 0 255 0 0 64 0> <"Cyan 50" 0 255 0 0 128 0> <"Tan" 0 0 57 131 0 0> <"Clay" 0 0 74 74 57 0> <"Brown" 0 30 100 220 30 0> <"Dark Brown" 0 60 135 190 65 0> <"Olive" 0 90 65 190 65 0> <"Light Orange" 0 0 33 255 0 0> <"Orange" 0 0 90 255 0 0> <"Dark Orange" 0 0 132 255 0 0> <"Light Purple" 0 31 153 0 0 0> <"Purple" 0 80 208 0 15 0> <"Dark Purple" 0 25 126 0 44 0> <"Color0" 0 0 51 102 0 0> <"Color1" 0 0 0 0 71 0> <"Color2" 0 0 0 0 51 0> <"Color3" 0 0 0 0 73 0> <"Color4" 0 181 0 181 61 0> <"Color5" 0 255 17 0 0 0> END COLORMAP FONT "Times" "Zapf Dingbats" "Swiss" "Morewingbats" "Dutch" "Courier" END FONT SESSION WIN_SIZE <7494 5134> AUTOGRID ON PAGEWID 11000 PAGEHYT 8500 PRINTWID 11000 PRINTHYT 8500 PRINTLAND ON SLIDE_STYLE <0 -1 1> BACKFILL <34 2 5 1000 0 0 0> LINEFILL <21 21 5 1000 0 0 0> SHADOW <11 0 15 15> FONT 2 REZ <1 603 603 -1214 -508> END SESSION SLIDE_MASTER S_EXT1 <105 85 9892 1504> S_EXT2 <105 1562 9892 7370> T_ATTR0 BACKFILL <7 7 0 0 0 0 0> V_SPACE <0 611 0> SIZE 440000 BOLD ON HOR_JUST CENTER L_SPACE 611 MARGINS <0 0 0 0> END T_ATTR0 T_ATTR1 END T_ATTR1 S_ATTR0 BACKFILL <20 20 0 0 0 0 0> PARA <-500 500 -500 1 1000 0 3 108> V_SPACE <333 444 0> SIZE 320000 BOLD OFF HOR_JUST LEFT L_SPACE 444 END S_ATTR0 S_ATTR1 END S_ATTR1 S_ATTR2 PARA <-500 1000 -500 1 1000 0 3 108> V_SPACE <28 389 0> SIZE 280000 END S_ATTR2 S_ATTR3 PARA <-500 1500 -500 1 1000 0 3 108> V_SPACE <28 333 0> SIZE 240000 END S_ATTR3 S_ATTR4 PARA <-500 2000 -500 1 1000 0 3 108> V_SPACE <28 306 0> SIZE 220000 END S_ATTR4 S_ATTR5 PARA <-500 2500 -500 1 1000 0 3 108> ITALICS ON END S_ATTR5 SLIDE_INFO SLIDE_STYLE <0 0 1> PAGE_BACKGD <0 0 1 17> C_SCHEME <7 7 20 20 21 21 34 2 23 27 44 12 1 0 0 0 0 0 0 0 0 0 0 11> END SLIDE_INFO .GRP BACKFILL <1 0 0 0 0 0 0> LINEFILL <1 2 5 1000 0 0 0> SHADOW <6 0 15 15> PARA <0 0 0 0 1000 1 0 111> V_SPACE <250 250 0> FONT 0 SIZE 180000 ITALICS OFF L_SPACE 250 MARGINS <125 125 250 62> END .GRP END SLIDE_MASTER HANDOUT_MASTER SLIDE_INFO SLIDE_STYLE <0 -1 1> END SLIDE_INFO .GRP END .GRP END HANDOUT_MASTER OUTLINE_MASTER SLIDE_INFO SLIDE_STYLE <0 -1 1> END SLIDE_INFO .GRP END .GRP END OUTLINE_MASTER NOTES_MASTER N_EXT1 <250 250 7249 4875> N_EXT2 <250 5125 7249 9749> N_ATTR0 BACKFILL <1 1 0 0 0 0 0> V_SPACE <28 250 0> FONT 4 MARGINS <0 0 0 0> END N_ATTR0 N_ATTR1 END N_ATTR1 N_ATTR2 PARA <0 500 0 0 1000 1 0 111> END N_ATTR2 N_ATTR3 PARA <0 1000 0 0 1000 1 0 111> END N_ATTR3 N_ATTR4 PARA <0 1500 0 0 1000 1 0 111> END N_ATTR4 N_ATTR5 PARA <0 2000 0 0 1000 1 0 111> END N_ATTR5 SLIDE_INFO SLIDE_STYLE <0 -1 1> END SLIDE_INFO .GRP BACKFILL <1 0 0 0 0 0 0> PARA <0 0 0 0 1000 1 0 111> V_SPACE <250 250 0> FONT 0 MARGINS <125 125 250 62> END .GRP END NOTES_MASTER SLIDE_INFO SLIDE_STYLE <0 -1 1> LAYOUT_ID <0 1 2 3 3> END SLIDE_INFO PICTURE .TMP AT (105,85) RECOLOR ON TEMPLATE_FLAGS <1 1 0 0> T_POS <105 85 9892 1504> .TXT AT (1452,209) RECOLOR ON TEMPLATED ON BACKFILL <7 7 0 0 0 0 0> LINEFILL <21 21 5 1000 0 0 0> SHADOW <11 0 15 15> V_SPACE <0 611 0> FONT 2 SIZE 440000 BOLD ON HOR_JUST CENTER L_SPACE 611 MARGINS <0 0 0 0> TXTXYOFF <-24 448> T_PNTS (0,448)(0,0)(6981,0)(6981,579)(0,579)(0,448)(6981,448) H_SPACE 9788 .STR "Cryptographic methods:" .TMP AT (105,1562) RECOLOR ON TEMPLATE_FLAGS <1 2 0 0> T_POS <105 1562 9892 7370> .TXT AT (2654,1695) RECOLOR ON TEMPLATED ON TXTXYOFF <-4 437> T_PNTS (0,437)(0,0)(4611,0)(4611,2403)(0,2403)(0,437)(4611,437) .STR "Three important\ncomponents of\ncryptographic\nsystems" .TXT AT (1959,6223) RECOLOR ON BACKFILL <20 20 5 1000 0 0 0> THICKNESS 0 PARA <0 0 0 0 1000 34 0 111> V_SPACE <0 333 0> SIZE 240000 BOLD OFF L_SPACE 333 TXTXYOFF <0 238> T_PNTS (0,238)(0,0)(5891,0)(5891,644)(0,644)(0,238)(5891,238) H_SPACE 0 .STR L_SPACE 250 "Recommended reading:\n\"Applied Cryptography\", Bruce Schneier" END PICTURE NOTES .GRP BACKFILL <34 2 5 1000 0 0 0> THICKNESS 1 PARA <0 0 0 0 1000 1 0 111> V_SPACE <0 250 0> SIZE 180000 HOR_JUST LEFT MARGINS <125 125 250 62> .TMP AT (250,250) RECOLOR ON TEMPLATE_FLAGS <5 14 0 0> T_POS <250 250 7249 4875> .VOID .TMP AT (250,5125) RECOLOR ON TEMPLATE_FLAGS <6 15 0 0> T_POS <250 5125 7249 9749> .VOID END .GRP END NOTES SLIDE_INFO SLIDE_STYLE <0 -1 1> LAYOUT_ID <1 2 12 12 12> END SLIDE_INFO PICTURE .TMP AT (105,85) RECOLOR ON TEMPLATE_FLAGS <1 0 0 0> T_POS <105 85 9892 1504> .TXT AT (1518,232) RECOLOR ON TEMPLATED ON BACKFILL <7 7 0 0 0 0 0> V_SPACE <0 611 0> SIZE 440000 BOLD ON HOR_JUST CENTER L_SPACE 611 MARGINS <0 0 0 0> TXTXYOFF <-1 448> T_PNTS (-3,446)(-3,-2)(6886,-2)(6886,577)(-3,577)(-3,446)(6886,446) H_SPACE 9788 .STR "Why use cryptography?" .TMP AT (105,1562) RECOLOR ON TEMPLATE_FLAGS <2 3 0 0> T_POS <105 1562 9892 7370> .TXT AT (68,1653) RECOLOR ON TEMPLATED ON BACKFILL <20 20 0 0 0 0 0> PARA <-500 500 -500 1 1000 0 3 108> V_SPACE <333 444 0> SIZE 320000 BOLD OFF HOR_JUST LEFT L_SPACE 444 TXTXYOFF <13 326> T_PNTS (-6,323)(-6,-3)(8733,-3)(8733,5653)(-6,5653)(-6,323)(8733,323) .STR "Can offer " .STR ITALICS ON "genuinely secure" .STR ITALICS OFF " solutions to important security problems" .STR PARA <-500 1000 -500 1 1000 0 3 108> V_SPACE <28 389 0> SIZE 280000 "\n\tS" .STR "ome governments forbid it" .STR PARA <-500 500 -500 1 1000 0 3 108> V_SPACE <333 444 0> SIZE 320000 "\nConfidentiality" .STR PARA <-500 1000 -500 1 1000 0 3 108> V_SPACE <28 389 0> SIZE 280000 "\n\tCan I be sure no-one else can see my data? (e.g. sniffing)" .STR PARA <-500 500 -500 1 1000 0 3 108> V_SPACE <333 444 0> SIZE 320000 "\nIntegrity" .STR PARA <-500 1000 -500 1 1000 0 3 108> V_SPACE <28 389 0> SIZE 280000 "\n\tHas my data been modified?" .STR PARA <-500 500 -500 1 1000 0 3 108> V_SPACE <333 444 0> SIZE 320000 "\nAuthentication" .STR PARA <-500 1000 -500 1 1000 0 3 108> V_SPACE <28 389 0> SIZE 280000 "\n\tAre you who you claim to be?" .STR "\n\tAccess controls (Authorisation)" END PICTURE NOTES .GRP BACKFILL <34 2 5 1000 0 0 0> PARA <0 0 0 0 1000 1 0 111> V_SPACE <0 250 0> SIZE 180000 L_SPACE 250 MARGINS <125 125 250 62> .TMP AT (250,250) RECOLOR ON TEMPLATE_FLAGS <5 14 0 0> T_POS <250 250 7249 4875> .VOID .TMP AT (250,5125) RECOLOR ON TEMPLATE_FLAGS <6 15 0 0> T_POS <250 5125 7249 9749> .VOID END .GRP END NOTES SLIDE_INFO SLIDE_STYLE <0 -1 1> LAYOUT_ID <0 1 2 3 3> END SLIDE_INFO PICTURE .TMP AT (105,85) RECOLOR ON TEMPLATE_FLAGS <1 1 0 0> T_POS <105 85 9892 1504> .TXT AT (502,225) RECOLOR ON TEMPLATED ON BACKFILL <7 7 0 0 0 0 0> V_SPACE <0 611 0> SIZE 440000 BOLD ON HOR_JUST CENTER L_SPACE 611 MARGINS <0 0 0 0> TXTXYOFF <-129 437> T_PNTS (-1,433)(-1,-4)(9165,-4)(9165,1174)(-1,1174)(-1,433)(9165,433) .STR "1. \"Private key\" or \"symmetric\" ciphers" .POL AT (250,3001) RECOLOR ON BACKFILL <34 2 5 1000 0 0 0> PARA <0 0 0 0 1000 34 0 111> V_SPACE <0 250 0> SIZE 180000 BOLD OFF HOR_JUST LEFT L_SPACE 250 MARGINS <125 125 250 62> PNTS (750,0)(0,0)(0,1500)(1000,1500)(1000,250)(750,0) .POL AT (1000,3001) RECOLOR ON BACKFILL <34 2 5 500 0 0 0> PNTS (250,250)(0,0)(0,250)(250,250) .POL AT (8749,3001) RECOLOR ON BACKFILL <34 2 5 1000 0 0 0> PNTS (750,0)(0,0)(0,1500)(1000,1500)(1000,250)(750,0) .POL AT (9499,3001) RECOLOR ON BACKFILL <34 2 5 500 0 0 0> PNTS (250,250)(0,0)(0,250)(250,250) .LINE AT (1500,3750) RECOLOR ON BACKFILL <34 2 5 1000 0 0 0> THICKNESS 56 R_ARROW 1 PNTS (0,0)(7000,0) .TXT AT (381,4556) RECOLOR ON BACKFILL <20 20 5 1000 0 0 0> THICKNESS 0 R_ARROW 0 V_SPACE <0 333 0> SIZE 240000 HOR_JUST CENTER L_SPACE 333 MARGINS <0 0 0 0> TXTXYOFF <-11 238> T_PNTS (0,238)(0,0)(703,0)(703,576)(0,576)(0,238)(703,238) H_SPACE 0 .STR L_SPACE 250 "clear\ntext" .TXT AT (8869,4556) RECOLOR ON L_SPACE 333 T_PNTS (0,238)(0,0)(703,0)(703,576)(0,576)(0,238)(703,238) .STR L_SPACE 250 "clear\ntext" .LINE AT (2250,4000) RECOLOR ON BACKFILL <34 2 5 1000 0 0 0> THICKNESS 1 R_ARROW 1 V_SPACE <0 250 0> SIZE 180000 HOR_JUST LEFT MARGINS <125 125 250 62> PNTS (0,750)(0,0) .TXT AT (2129,4836) RECOLOR ON BACKFILL <20 20 5 1000 0 0 0> THICKNESS 0 R_ARROW 0 V_SPACE <0 667 0> SIZE 480000 HOR_JUST CENTER L_SPACE 667 MARGINS <0 0 0 0> TXTXYOFF <-39 476> T_PNTS (0,476)(0,0)(281,0)(281,477)(0,477)(0,476)(281,476) .STR L_SPACE 250 "k" .LINE AT (7499,4002) RECOLOR ON BACKFILL <34 2 5 1000 0 0 0> THICKNESS 1 R_ARROW 1 V_SPACE <0 250 0> SIZE 180000 HOR_JUST LEFT MARGINS <125 125 250 62> PNTS (0,750)(0,0) .TXT AT (7374,4838) RECOLOR ON BACKFILL <20 20 5 1000 0 0 0> THICKNESS 0 R_ARROW 0 V_SPACE <0 667 0> SIZE 480000 HOR_JUST CENTER L_SPACE 667 MARGINS <0 0 0 0> T_PNTS (0,476)(0,0)(281,0)(281,477)(0,477)(0,476)(281,476) .STR L_SPACE 250 "k" .TXT AT (4250,3811) RECOLOR ON BACKFILL <7 20 5 1000 0 0 0> V_SPACE <0 333 0> SIZE 240000 BOLD ON L_SPACE 333 TXTXYOFF <-11 238> T_PNTS (0,238)(0,0)(980,0)(980,576)(0,576)(0,238)(980,238) .STR L_SPACE 250 "cipher\ntext" .TXT AT (729,6172) RECOLOR ON BACKFILL <20 20 5 1000 0 0 0> V_SPACE <0 417 0> SIZE 300000 BOLD OFF L_SPACE 417 TXTXYOFF <-3 298> T_PNTS (0,298)(0,0)(8612,0)(8612,807)(0,807)(0,298)(8612,298) .STR L_SPACE 250 "The same key is used to encrypt the document\nbefore sending an d decrypt it at the far end" .GRP BACKFILL <34 2 5 1000 0 0 0> THICKNESS 1 PARA <0 0 0 0 1000 1 0 111> V_SPACE <0 250 0> SIZE 180000 HOR_JUST LEFT MARGINS <125 125 250 62> .ELL AT (2000,3500) RECOLOR ON BACKFILL <7 2 5 1000 0 0 0> PARA <0 0 0 0 1000 34 0 111> PNTS (0,0)(500,0)(500,500)(0,500)(0,0) .LINE AT (2080,3573) RECOLOR ON BACKFILL <34 2 5 1000 0 0 0> LINEFILL <1 21 5 1000 0 0 0> THICKNESS 42 PNTS (0,354)(347,0) .LINE AT (2087,3586) RECOLOR ON PNTS (0,0)(340,341) END .GRP .GRP LINEFILL <21 21 5 1000 0 0 0> THICKNESS 1 PARA <0 0 0 0 1000 1 0 111> .ELL AT (7249,3502) RECOLOR ON BACKFILL <7 2 5 1000 0 0 0> PARA <0 0 0 0 1000 34 0 111> PNTS (0,0)(500,0)(500,500)(0,500)(0,0) .LINE AT (7329,3575) RECOLOR ON BACKFILL <34 2 5 1000 0 0 0> LINEFILL <1 21 5 1000 0 0 0> THICKNESS 42 PNTS (0,354)(347,0) .LINE AT (7336,3588) RECOLOR ON PNTS (0,0)(340,341) END .GRP END PICTURE NOTES .GRP LINEFILL <21 21 5 1000 0 0 0> THICKNESS 1 PARA <0 0 0 0 1000 1 0 111> .TMP AT (250,250) RECOLOR ON TEMPLATE_FLAGS <5 14 0 0> T_POS <250 250 7249 4875> .VOID .TMP AT (250,5125) RECOLOR ON TEMPLATE_FLAGS <6 15 0 0> T_POS <250 5125 7249 9749> .VOID END .GRP END NOTES SLIDE_INFO SLIDE_STYLE <0 -1 1> LAYOUT_ID <1 2 12 12 12> END SLIDE_INFO PICTURE .TMP AT (105,85) RECOLOR ON TEMPLATE_FLAGS <1 0 0 0> T_POS <105 85 9892 1504> .TXT AT (430,222) RECOLOR ON TEMPLATED ON BACKFILL <7 7 0 0 0 0 0> V_SPACE <0 611 0> SIZE 440000 BOLD ON HOR_JUST CENTER L_SPACE 611 MARGINS <0 0 0 0> TXTXYOFF <-87 437> T_PNTS (-3,435)(-3,-2)(9235,-2)(9235,1176)(-3,1176)(-3,435)(9235,435) H_SPACE 9788 .STR "We assume an eavesdropper is able to intercept the ciphertext" .TMP AT (105,1562) RECOLOR ON TEMPLATE_FLAGS <2 3 0 0> T_POS <105 1562 9892 7370> .TXT AT (58,1645) RECOLOR ON TEMPLATED ON BACKFILL <20 20 0 0 0 0 0> PARA <-500 500 -500 1 1000 0 3 108> V_SPACE <333 444 0> SIZE 320000 BOLD OFF HOR_JUST LEFT L_SPACE 444 TXTXYOFF <13 326> T_PNTS (-6,323)(-6,-3)(7529,-3)(7529,421)(-6,421)(-6,323)(7529,323) .STR "How can they recover the cleartext?" END PICTURE NOTES .GRP BACKFILL <34 2 5 1000 0 0 0> PARA <0 0 0 0 1000 1 0 111> V_SPACE <0 250 0> SIZE 180000 L_SPACE 250 MARGINS <125 125 250 62> .TMP AT (250,250) RECOLOR ON TEMPLATE_FLAGS <5 14 0 0> T_POS <250 250 7249 4875> .VOID .TMP AT (250,5125) RECOLOR ON TEMPLATE_FLAGS <6 15 0 0> T_POS <250 5125 7249 9749> .VOID END .GRP END NOTES SLIDE_INFO SLIDE_STYLE <0 -1 1> LAYOUT_ID <1 2 12 12 12> END SLIDE_INFO PICTURE .TMP AT (105,85) RECOLOR ON TEMPLATE_FLAGS <1 0 0 0> T_POS <105 85 9892 1504> .TXT AT (450,223) RECOLOR ON TEMPLATED ON BACKFILL <7 7 0 0 0 0 0> V_SPACE <0 611 0> SIZE 440000 BOLD ON HOR_JUST CENTER L_SPACE 611 MARGINS <0 0 0 0> TXTXYOFF <-44 438> T_PNTS (-3,435)(-3,-3)(9071,-3)(9071,566)(-3,566)(-3,435)(9071,435) .STR "Examples of symmetric ciphers" .TMP AT (105,1562) RECOLOR ON TEMPLATE_FLAGS <2 3 0 0> T_POS <105 1562 9892 7370> .TXT AT (46,1630) RECOLOR ON TEMPLATED ON BACKFILL <20 20 0 0 0 0 0> PARA <-500 500 -500 1 1000 0 3 108> V_SPACE <333 444 0> SIZE 320000 BOLD OFF HOR_JUST LEFT L_SPACE 444 TXTXYOFF <13 326> T_PNTS (-5,323)(-5,-3)(9176,-3)(9176,5299)(-5,5299)(-5,323)(9176,323) .STR "DES - 56 bit key length, designed by US security service" .STR "\n3DES - effective key length 112 bits" .STR "\nAES (Advanced Encryption Standard) - 128 to 256 bit key lengt h" .STR "\nBlowfish - 128 bits, optimised for fast operation on 32-bit m icroprocessors" .STR "\nIDEA - 128 bits, patented (requires a licence for commercial use)" END PICTURE NOTES .GRP BACKFILL <34 2 5 1000 0 0 0> PARA <0 0 0 0 1000 1 0 111> V_SPACE <0 250 0> SIZE 180000 L_SPACE 250 MARGINS <125 125 250 62> .TMP AT (250,250) RECOLOR ON TEMPLATE_FLAGS <5 14 0 0> T_POS <250 250 7249 4875> .VOID .TMP AT (250,5125) RECOLOR ON TEMPLATE_FLAGS <6 15 0 0> T_POS <250 5125 7249 9749> .VOID END .GRP END NOTES SLIDE_INFO SLIDE_STYLE <0 -1 1> LAYOUT_ID <1 2 12 12 12> END SLIDE_INFO PICTURE .TMP AT (105,85) RECOLOR ON TEMPLATE_FLAGS <1 0 0 0> T_POS <105 85 9892 1504> .TXT AT (601,223) RECOLOR ON TEMPLATED ON BACKFILL <7 7 0 0 0 0 0> V_SPACE <0 611 0> SIZE 440000 BOLD ON HOR_JUST CENTER L_SPACE 611 MARGINS <0 0 0 0> TXTXYOFF <-44 438> T_PNTS (-3,435)(-3,-3)(8763,-3)(8763,566)(-3,566)(-3,435)(8763,435) .STR "Features of symmetric ciphers" .TMP AT (105,1562) RECOLOR ON TEMPLATE_FLAGS <2 3 0 0> T_POS <105 1562 9892 7370> .TXT AT (58,1648) RECOLOR ON TEMPLATED ON BACKFILL <20 20 0 0 0 0 0> PARA <-500 500 -500 1 1000 0 3 108> V_SPACE <333 444 0> SIZE 320000 BOLD OFF HOR_JUST LEFT L_SPACE 444 TXTXYOFF <13 322> T_PNTS (-6,320)(-6,-2)(8991,-2)(8991,5332)(-6,5332)(-6,320)(8991,320) .STR "Fast to encrypt and decrypt, suitable for large volumes of data " .STR "\nA well-designed cipher is only subject to brute-force attack; the strength is therefore directly related to the key length" .STR "\nCurrent recommendation is a key length of at least 90 bits" .STR PARA <-500 1000 -500 1 1000 0 3 108> V_SPACE <28 389 0> SIZE 280000 "\n\ti.e. to be fairly sure that your data will be safe for at l east 20 years" .STR PARA <-500 500 -500 1 1000 0 3 108> V_SPACE <333 444 0> SIZE 320000 "\nProblem - how do you distribute the keys?" END PICTURE NOTES .GRP BACKFILL <34 2 5 1000 0 0 0> PARA <0 0 0 0 1000 1 0 111> V_SPACE <0 250 0> SIZE 180000 L_SPACE 250 MARGINS <125 125 250 62> .TMP AT (250,250) RECOLOR ON TEMPLATE_FLAGS <5 14 0 0> T_POS <250 250 7249 4875> .VOID .TMP AT (250,5125) RECOLOR ON TEMPLATE_FLAGS <6 15 0 0> T_POS <250 5125 7249 9749> .VOID END .GRP END NOTES SLIDE_INFO SLIDE_STYLE <0 -1 1> LAYOUT_ID <0 1 2 3 3> END SLIDE_INFO PICTURE .TMP AT (105,85) RECOLOR ON TEMPLATE_FLAGS <1 1 0 0> T_POS <105 85 9892 1504> .TXT AT (1662,217) RECOLOR ON TEMPLATED ON BACKFILL <7 7 0 0 0 0 0> V_SPACE <0 611 0> SIZE 440000 BOLD ON HOR_JUST CENTER L_SPACE 611 MARGINS <0 0 0 0> TXTXYOFF <-94 437> T_PNTS (-1,435)(-1,-2)(6785,-2)(6785,1177)(-1,1177)(-1,435)(6785,435) .STR "2. \"Hashing\" - one-way encryption" .POL AT (250,3001) RECOLOR ON BACKFILL <34 2 5 1000 0 0 0> PARA <0 0 0 0 1000 34 0 111> V_SPACE <0 250 0> SIZE 180000 BOLD OFF HOR_JUST LEFT L_SPACE 250 MARGINS <125 125 250 62> PNTS (750,0)(0,0)(0,1500)(1000,1500)(1000,250)(750,0) .POL AT (1000,3001) RECOLOR ON BACKFILL <34 2 5 500 0 0 0> PNTS (250,250)(0,0)(0,250)(250,250) .LINE AT (1500,3750) RECOLOR ON BACKFILL <34 2 5 1000 0 0 0> THICKNESS 56 R_ARROW 1 PNTS (0,0)(4000,0) .TXT AT (381,4556) RECOLOR ON BACKFILL <20 20 5 1000 0 0 0> THICKNESS 0 R_ARROW 0 V_SPACE <0 333 0> SIZE 240000 HOR_JUST CENTER L_SPACE 333 MARGINS <0 0 0 0> TXTXYOFF <-11 238> T_PNTS (0,238)(0,0)(703,0)(703,576)(0,576)(0,238)(703,238) H_SPACE 0 .STR L_SPACE 250 "clear\ntext" .TXT AT (589,5665) RECOLOR ON V_SPACE <0 417 0> SIZE 300000 L_SPACE 417 TXTXYOFF <1 298> T_PNTS (0,298)(0,0)(9011,0)(9011,1224)(0,1224)(0,298)(9011,298) .STR L_SPACE 250 "Munging the document gives a short\n\"message digest\" (checksu m). Not possible to go\nback from the digest to the original doc ument." .RECT AT (6000,3500) RECOLOR ON BACKFILL <12 11 0 6 0 0 0> THICKNESS 1 V_SPACE <0 250 0> SIZE 180000 HOR_JUST LEFT MARGINS <125 125 250 62> PNTS (0,0)(2750,0)(2750,500)(0,500)(0,0) .TXT AT (5957,4116) RECOLOR ON BACKFILL <7 20 5 1000 0 0 0> THICKNESS 0 V_SPACE <0 333 0> SIZE 240000 HOR_JUST CENTER L_SPACE 333 MARGINS <0 0 0 0> TXTXYOFF <1 238> T_PNTS (0,238)(0,0)(2930,0)(2930,644)(0,644)(0,238)(2930,238) .STR L_SPACE 250 "Fixed length \"hash\"\nor \"message digest\"" .TXT AT (2803,4223) RECOLOR ON BOLD ON L_SPACE 333 T_PNTS (0,238)(0,0)(1288,0)(1288,576)(0,576)(0,238)(1288,238) .STR L_SPACE 250 "hashing\nfunction" .GRP BACKFILL <34 2 5 1000 0 0 0> THICKNESS 1 PARA <0 0 0 0 1000 1 0 111> V_SPACE <0 250 0> SIZE 180000 BOLD OFF HOR_JUST LEFT MARGINS <125 125 250 62> .ELL AT (3249,3500) RECOLOR ON BACKFILL <12 2 5 1000 0 0 0> PARA <0 0 0 0 1000 34 0 111> PNTS (0,0)(500,0)(500,500)(0,500)(0,0) .LINE AT (3329,3573) RECOLOR ON BACKFILL <34 2 5 1000 0 0 0> LINEFILL <1 21 5 1000 0 0 0> THICKNESS 42 PNTS (0,354)(347,0) .LINE AT (3336,3586) RECOLOR ON PNTS (0,0)(340,341) END .GRP END PICTURE NOTES .GRP LINEFILL <21 21 5 1000 0 0 0> THICKNESS 1 PARA <0 0 0 0 1000 1 0 111> .TMP AT (250,250) RECOLOR ON TEMPLATE_FLAGS <5 14 0 0> T_POS <250 250 7249 4875> .VOID .TMP AT (250,5125) RECOLOR ON TEMPLATE_FLAGS <6 15 0 0> T_POS <250 5125 7249 9749> .VOID END .GRP END NOTES SLIDE_INFO SLIDE_STYLE <0 -1 1> LAYOUT_ID <1 2 12 12 12> END SLIDE_INFO PICTURE .TMP AT (105,85) RECOLOR ON TEMPLATE_FLAGS <1 0 0 0> T_POS <105 85 9892 1504> .TXT AT (3603,225) RECOLOR ON TEMPLATED ON BACKFILL <7 7 0 0 0 0 0> V_SPACE <0 611 0> SIZE 440000 BOLD ON HOR_JUST CENTER L_SPACE 611 MARGINS <0 0 0 0> TXTXYOFF <-44 437> T_PNTS (-4,433)(-4,-4)(2777,-4)(2777,563)(-4,563)(-4,433)(2777,433) H_SPACE 9788 .STR "Examples" .TMP AT (105,1562) RECOLOR ON TEMPLATE_FLAGS <2 3 0 0> T_POS <105 1562 9892 7370> .TXT AT (38,1625) RECOLOR ON TEMPLATED ON BACKFILL <20 20 0 0 0 0 0> PARA <-500 500 -500 1 1000 0 3 108> V_SPACE <333 444 0> SIZE 320000 BOLD OFF HOR_JUST LEFT L_SPACE 444 TXTXYOFF <13 326> T_PNTS (-2,323)(-2,-3)(9197,-3)(9197,4862)(-2,4862)(-2,323)(9197,323) .STR "Unix crypt() function, based on DES" .STR "\nMD5 (Message Digest 5) - 128 bit hash" .STR "\nSHA1 (Secure Hash Algorithm) - 160 bits" .STR "\nNo two documents have yet been discovered which have the same MD5 digest!" .STR "\nNo feasible method to create any document which has a given M D5 digest" END PICTURE NOTES .GRP BACKFILL <34 2 5 1000 0 0 0> PARA <0 0 0 0 1000 1 0 111> V_SPACE <0 250 0> SIZE 180000 L_SPACE 250 MARGINS <125 125 250 62> .TMP AT (250,250) RECOLOR ON TEMPLATE_FLAGS <5 14 0 0> T_POS <250 250 7249 4875> .VOID .TMP AT (250,5125) RECOLOR ON TEMPLATE_FLAGS <6 15 0 0> T_POS <250 5125 7249 9749> .VOID END .GRP END NOTES SLIDE_INFO SLIDE_STYLE <0 -1 1> LAYOUT_ID <1 2 12 12 12> END SLIDE_INFO PICTURE .TMP AT (105,85) RECOLOR ON TEMPLATE_FLAGS <1 0 0 0> T_POS <105 85 9892 1504> .TXT AT (2043,193) RECOLOR ON TEMPLATED ON BACKFILL <7 7 0 0 0 0 0> V_SPACE <0 611 0> SIZE 440000 BOLD ON HOR_JUST CENTER L_SPACE 611 MARGINS <0 0 0 0> TXTXYOFF <-23 448> T_PNTS (-3,446)(-3,-2)(5814,-2)(5814,1188)(-3,1188)(-3,446)(5814,446) .STR "So what use is that?\na. Integrity checks" .TMP AT (105,1562) RECOLOR ON TEMPLATE_FLAGS <2 3 0 0> T_POS <105 1562 9892 7370> .TXT AT (38,1628) RECOLOR ON TEMPLATED ON BACKFILL <20 20 0 0 0 0 0> PARA <-500 500 -500 1 1000 0 3 108> V_SPACE <333 444 0> SIZE 320000 BOLD OFF HOR_JUST LEFT L_SPACE 444 TXTXYOFF <11 322> T_PNTS (-3,320)(-3,-2)(9038,-2)(9038,3304)(-3,3304)(-3,320)(9038,320) .STR "You can run many megabytes of data through MD5 and still get on ly 128 bits to check" .STR "\nAn attacker cannot feasibly modify your file and leave it wit h the same MD5 checksum" .STR "\nGives your document a unique \"fingerprint\"" END PICTURE NOTES .GRP BACKFILL <34 2 5 1000 0 0 0> PARA <0 0 0 0 1000 1 0 111> V_SPACE <0 250 0> SIZE 180000 L_SPACE 250 MARGINS <125 125 250 62> .TMP AT (250,250) RECOLOR ON TEMPLATE_FLAGS <5 14 0 0> T_POS <250 250 7249 4875> .VOID .TMP AT (250,5125) RECOLOR ON TEMPLATE_FLAGS <6 15 0 0> T_POS <250 5125 7249 9749> .VOID END .GRP END NOTES SLIDE_INFO SLIDE_STYLE <0 -1 1> LAYOUT_ID <1 2 12 12 12> END SLIDE_INFO PICTURE .TMP AT (105,85) RECOLOR ON TEMPLATE_FLAGS <1 0 0 0> T_POS <105 85 9892 1504> .TXT AT (3760,217) RECOLOR ON TEMPLATED ON BACKFILL <7 7 0 0 0 0 0> V_SPACE <0 611 0> SIZE 440000 BOLD ON HOR_JUST CENTER L_SPACE 611 MARGINS <0 0 0 0> TXTXYOFF <-44 437> T_PNTS (-3,435)(-3,-2)(2442,-2)(2442,445)(-3,445)(-3,435)(2442,435) .STR "Exercise" .TMP AT (105,1562) RECOLOR ON TEMPLATE_FLAGS <2 3 0 0> T_POS <105 1562 9892 7370> .TXT AT (51,1644) RECOLOR ON TEMPLATED ON BACKFILL <20 20 0 0 0 0 0> PARA <-500 500 -500 1 1000 0 3 108> V_SPACE <333 444 0> SIZE 320000 BOLD OFF HOR_JUST LEFT L_SPACE 444 TXTXYOFF <13 317> T_PNTS (-5,316)(-5,-1)(9063,-1)(9063,5600)(-5,5600)(-5,316)(9063,316) .STR "Exercise: on your machine type" .STR PARA <-500 1000 -500 1 1000 0 3 108> V_SPACE <28 389 0> SIZE 280000 "\n\tcat /etc/aliases" .STR PARA <-500 500 -500 1 1000 0 3 108> V_SPACE <333 444 0> SIZE 320000 "\nLook at your neighbour's machine. Is their file " .STR ITALICS ON "exactly" .STR ITALICS OFF " the same as yours? Can you be sure?" .STR "\nmd5sum /etc/aliases" .STR PARA <-500 1000 -500 1 1000 0 3 108> V_SPACE <28 389 0> SIZE 280000 "\n\tCompare the result with your neighbour" .STR PARA <-500 500 -500 1 1000 0 3 108> V_SPACE <333 444 0> SIZE 320000 "\nNow change ONE character in /etc/aliases and repeat the md5su m test" .STR "\nUnder FreeBSD the command is \"md5\"" END PICTURE NOTES .GRP BACKFILL <34 2 5 1000 0 0 0> PARA <0 0 0 0 1000 1 0 111> V_SPACE <0 250 0> SIZE 180000 L_SPACE 250 MARGINS <125 125 250 62> .TMP AT (250,250) RECOLOR ON TEMPLATE_FLAGS <5 14 0 0> T_POS <250 250 7249 4875> .VOID .TMP AT (250,5125) RECOLOR ON TEMPLATE_FLAGS <6 15 0 0> T_POS <250 5125 7249 9749> .VOID END .GRP END NOTES SLIDE_INFO SLIDE_STYLE <0 -1 1> LAYOUT_ID <1 2 12 12 12> END SLIDE_INFO PICTURE .TMP AT (105,85) RECOLOR ON TEMPLATE_FLAGS <1 0 0 0> T_POS <105 85 9892 1504> .TXT AT (478,228) RECOLOR ON TEMPLATED ON BACKFILL <7 7 0 0 0 0 0> V_SPACE <0 611 0> SIZE 440000 BOLD ON HOR_JUST CENTER L_SPACE 611 MARGINS <0 0 0 0> TXTXYOFF <-109 448> T_PNTS (-1,445)(-1,-3)(9202,-3)(9202,1070)(-1,1070)(-1,445)(9202,445) .STR "Software announcements often contain an MD5 checksum" .TMP AT (105,1562) RECOLOR ON TEMPLATE_FLAGS <2 3 0 0> T_POS <105 1562 9892 7370> .TXT AT (73,1668) RECOLOR ON TEMPLATED ON BACKFILL <20 20 0 0 0 0 0> PARA <-500 500 -500 1 1000 0 3 108> V_SPACE <333 444 0> SIZE 320000 BOLD OFF HOR_JUST LEFT L_SPACE 444 TXTXYOFF <13 317> T_PNTS (-2,315)(-2,-2)(8722,-2)(8722,1544)(-2,1544)(-2,315)(8722,315) .STR "It's trivial to check" .STR "\nProtects you against hacked FTP servers and download errors" .TXT AT (250,3749) RECOLOR ON BACKFILL <20 20 5 1000 0 0 0> THICKNESS 0 PARA <0 0 0 0 1000 34 0 111> V_SPACE <0 250 0> FONT 5 SIZE 180000 L_SPACE 250 MARGINS <125 125 250 62> TXTXYOFF <0 0> PNTS (0,0)(9500,0)(9500,1252)(0,1252)(0,0) H_SPACE 0 .STR "$ " .STR BOLD ON "md5sum exim-4.30.tar.bz2" .STR BOLD OFF " \nbe53ba6801a019452f06b68c112a2ec1 exim-4.30.tar.bz2\n$ " .TXT AT (1947,5496) RECOLOR ON BACKFILL <7 20 5 1000 0 0 0> V_SPACE <0 333 0> FONT 2 SIZE 240000 HOR_JUST CENTER L_SPACE 333 MARGINS <0 0 0 0> TXTXYOFF <1 245> T_PNTS (0,245)(0,0)(5059,0)(5059,583)(0,583)(0,245)(5059,245) .STR L_SPACE 250 "Could the attacker have modified\nthe announcement E-mail as we ll?" END PICTURE NOTES .GRP BACKFILL <34 2 5 1000 0 0 0> THICKNESS 1 PARA <0 0 0 0 1000 1 0 111> V_SPACE <0 250 0> SIZE 180000 HOR_JUST LEFT MARGINS <125 125 250 62> .TMP AT (250,250) RECOLOR ON TEMPLATE_FLAGS <5 14 0 0> T_POS <250 250 7249 4875> .VOID .TMP AT (250,5125) RECOLOR ON TEMPLATE_FLAGS <6 15 0 0> T_POS <250 5125 7249 9749> .VOID END .GRP END NOTES SLIDE_INFO SLIDE_STYLE <0 -1 1> LAYOUT_ID <1 2 12 12 12> END SLIDE_INFO PICTURE .TMP AT (105,85) RECOLOR ON TEMPLATE_FLAGS <1 0 0 0> T_POS <105 85 9892 1504> .TXT AT (421,198) RECOLOR ON TEMPLATED ON BACKFILL <7 7 0 0 0 0 0> V_SPACE <0 611 0> SIZE 440000 BOLD ON HOR_JUST CENTER L_SPACE 611 MARGINS <0 0 0 0> TXTXYOFF <1 448> T_PNTS (-2,446)(-2,-2)(9039,-2)(9039,1188)(-2,1188)(-2,446)(9039,446) H_SPACE 9788 .STR "So what use is that?\nb. Encrypted password storage" .TMP AT (105,1562) RECOLOR ON TEMPLATE_FLAGS <2 3 0 0> T_POS <105 1562 9892 7370> .TXT AT (51,1639) RECOLOR ON TEMPLATED ON BACKFILL <20 20 0 0 0 0 0> PARA <-500 500 -500 1 1000 0 3 108> V_SPACE <333 444 0> SIZE 320000 BOLD OFF HOR_JUST LEFT L_SPACE 444 TXTXYOFF <13 322> T_PNTS (-5,321)(-5,-1)(9273,-1)(9273,5742)(-5,5742)(-5,321)(9273,321) .STR "We don't want to keep cleartext passwords if possible; the pass word file would be far too attractive a target" .STR "\nStore hash(passwd) in /etc/shadow" .STR "\nWhen user logs in, calculate the hash of the password they ha ve given, and compare it to the hash in the password file" .STR "\nIf the two hashes match, the user must have entered the corre ct password" .STR "\nCan an attacker still recover the password?" END PICTURE NOTES .GRP BACKFILL <34 2 5 1000 0 0 0> PARA <0 0 0 0 1000 1 0 111> V_SPACE <0 250 0> SIZE 180000 L_SPACE 250 MARGINS <125 125 250 62> .TMP AT (250,250) RECOLOR ON TEMPLATE_FLAGS <5 14 0 0> T_POS <250 250 7249 4875> .VOID .TMP AT (250,5125) RECOLOR ON TEMPLATE_FLAGS <6 15 0 0> T_POS <250 5125 7249 9749> .VOID END .GRP END NOTES SLIDE_INFO SLIDE_STYLE <0 -1 1> LAYOUT_ID <1 2 12 12 12> END SLIDE_INFO PICTURE .TMP AT (105,85) RECOLOR ON TEMPLATE_FLAGS <1 0 0 0> T_POS <105 85 9892 1504> .TXT AT (449,205) RECOLOR ON TEMPLATED ON BACKFILL <7 7 0 0 0 0 0> V_SPACE <0 611 0> SIZE 440000 BOLD ON HOR_JUST CENTER L_SPACE 611 MARGINS <0 0 0 0> TXTXYOFF <1 448> T_PNTS (-2,447)(-2,-1)(8993,-1)(8993,1072)(-2,1072)(-2,447)(8993,447) .STR "So what use is that?\nc. Shared secret authentication" .TMP AT (105,1562) RECOLOR ON TEMPLATE_FLAGS <2 3 0 0> T_POS <105 1562 9892 7370> .TXT AT (58,1653) RECOLOR ON TEMPLATED ON BACKFILL <20 20 0 0 0 0 0> PARA <-500 500 -500 1 1000 0 3 108> V_SPACE <333 444 0> SIZE 320000 BOLD OFF HOR_JUST LEFT L_SPACE 444 TXTXYOFF <13 317> T_PNTS (-6,315)(-6,-2)(9037,-2)(9037,2079)(-6,2079)(-6,315)(9037,315) .STR "Using hashing, a user can prove that they possess a password, w ithout actually sending it over the wire" .STR "\nUsually called a \"shared secret\" in this case" .LINE AT (1500,4749) RECOLOR ON BACKFILL <34 2 5 1000 0 0 0> THICKNESS 56 R_ARROW 1 PARA <0 0 0 0 1000 34 0 111> V_SPACE <0 250 0> SIZE 180000 L_SPACE 250 MARGINS <125 125 250 62> PNTS (6500,0)(0,0) .TXT AT (8273,4465) RECOLOR ON BACKFILL <20 20 5 1000 0 0 0> THICKNESS 0 R_ARROW 0 V_SPACE <0 500 0> SIZE 360000 HOR_JUST CENTER L_SPACE 500 MARGINS <0 0 0 0> TXTXYOFF <-21 367> T_PNTS (0,367)(0,0)(1443,0)(1443,376)(0,376)(0,367)(1443,367) H_SPACE 0 .STR L_SPACE 250 "Server" .TXT AT (70,4561) RECOLOR ON L_SPACE 500 T_PNTS (0,367)(0,0)(1241,0)(1241,379)(0,379)(0,367)(1241,367) .STR L_SPACE 250 "Client" .LINE AT (1502,5497) RECOLOR ON BACKFILL <34 2 5 1000 0 0 0> THICKNESS 56 L_ARROW 1 V_SPACE <0 250 0> SIZE 180000 HOR_JUST LEFT MARGINS <125 125 250 62> PNTS (6500,0)(0,0) .TXT AT (4055,4312) RECOLOR ON BACKFILL <7 20 5 1000 0 0 0> THICKNESS 0 L_ARROW 0 V_SPACE <0 333 0> SIZE 240000 HOR_JUST CENTER L_SPACE 333 MARGINS <0 0 0 0> TXTXYOFF <-13 245> T_PNTS (0,245)(0,0)(1471,0)(1471,318)(0,318)(0,245)(1471,245) .STR L_SPACE 250 "Challenge" .TXT AT (2927,5081) RECOLOR ON L_SPACE 333 TXTXYOFF <-21 245> T_PNTS (0,245)(0,0)(3731,0)(3731,318)(0,318)(0,245)(3731,245) .STR L_SPACE 250 "hash(Challenge + Secret)" .TXT AT (1121,5907) RECOLOR ON BACKFILL <20 20 5 1000 0 0 0> V_SPACE <0 417 0> SIZE 300000 L_SPACE 417 TXTXYOFF <1 306> T_PNTS (0,306)(0,0)(7450,0)(7450,1149)(0,1149)(0,306)(7450,306) .STR L_SPACE 250 "Server recalculates the hash using the\nchallenge it sent and i ts local copy of the\nsecret. OK if both hashes match." END PICTURE NOTES .GRP BACKFILL <34 2 5 1000 0 0 0> THICKNESS 1 PARA <0 0 0 0 1000 1 0 111> V_SPACE <0 250 0> SIZE 180000 HOR_JUST LEFT MARGINS <125 125 250 62> .TMP AT (250,250) RECOLOR ON TEMPLATE_FLAGS <5 14 0 0> T_POS <250 250 7249 4875> .VOID .TMP AT (250,5125) RECOLOR ON TEMPLATE_FLAGS <6 15 0 0> T_POS <250 5125 7249 9749> .VOID END .GRP END NOTES SLIDE_INFO SLIDE_STYLE <0 -1 1> LAYOUT_ID <1 2 12 12 12> END SLIDE_INFO PICTURE .TMP AT (105,85) RECOLOR ON TEMPLATE_FLAGS <1 0 0 0> T_POS <105 85 9892 1504> .TXT AT (1633,222) RECOLOR ON TEMPLATED ON BACKFILL <7 7 0 0 0 0 0> V_SPACE <0 611 0> SIZE 440000 BOLD ON HOR_JUST CENTER L_SPACE 611 MARGINS <0 0 0 0> TXTXYOFF <-127 437> T_PNTS (-2,435)(-2,-2)(6857,-2)(6857,1056)(-2,1056)(-2,435)(6857,435) H_SPACE 9788 .STR "Notes on shared secret authentication" .TMP AT (105,1562) RECOLOR ON TEMPLATE_FLAGS <2 3 0 0> T_POS <105 1562 9892 7370> .TXT AT (53,1640) RECOLOR ON TEMPLATED ON BACKFILL <20 20 0 0 0 0 0> PARA <-500 500 -500 1 1000 0 3 108> V_SPACE <333 444 0> SIZE 320000 BOLD OFF HOR_JUST LEFT L_SPACE 444 TXTXYOFF <13 326> T_PNTS (-2,323)(-2,-3)(9157,-3)(9157,4105)(-2,4105)(-2,323)(9157,323) .STR "Examples: APOP, CRAM-MD5" .STR "\nSniffer cannot see the secret - but they " .STR ITALICS ON "can" .STR ITALICS OFF " see the challenge and hash of (challenge + secret). This will allow them to try dictionary and brute-force attacks to recover the secret." .STR "\nThe secret must be stored in PLAIN TEXT on the server for thi s method to work." END PICTURE NOTES .GRP BACKFILL <34 2 5 1000 0 0 0> PARA <0 0 0 0 1000 1 0 111> V_SPACE <0 250 0> SIZE 180000 L_SPACE 250 MARGINS <125 125 250 62> .TMP AT (250,250) RECOLOR ON TEMPLATE_FLAGS <5 14 0 0> T_POS <250 250 7249 4875> .VOID .TMP AT (250,5125) RECOLOR ON TEMPLATE_FLAGS <6 15 0 0> T_POS <250 5125 7249 9749> .VOID END .GRP END NOTES SLIDE_INFO SLIDE_STYLE <0 -1 1> LAYOUT_ID <1 2 12 12 12> END SLIDE_INFO PICTURE .TMP AT (105,85) RECOLOR ON TEMPLATE_FLAGS <1 0 0 0> T_POS <105 85 9892 1504> .TXT AT (600,202) RECOLOR ON TEMPLATED ON BACKFILL <7 7 0 0 0 0 0> V_SPACE <0 611 0> SIZE 440000 BOLD ON HOR_JUST CENTER L_SPACE 611 MARGINS <0 0 0 0> TXTXYOFF <0 448> T_PNTS (-3,447)(-3,-1)(8701,-1)(8701,1189)(-3,1189)(-3,447)(8701,447) .STR "So what use is that?\nd. Generating encryption keys" .TMP AT (105,1562) RECOLOR ON TEMPLATE_FLAGS <2 3 0 0> T_POS <105 1562 9892 7370> .TXT AT (33,1640) RECOLOR ON TEMPLATED ON BACKFILL <20 20 0 0 0 0 0> PARA <-500 500 -500 1 1000 0 3 108> V_SPACE <333 444 0> SIZE 320000 BOLD OFF HOR_JUST LEFT L_SPACE 444 TXTXYOFF <13 317> T_PNTS (-5,315)(-5,-2)(9260,-2)(9260,4960)(-5,4960)(-5,315)(9260,315) .STR "Users cannot remember 128 bit binary encryption keys" .STR "\nHowever they can remember \"passphrases\" " .STR "\nA hash can be used to convert a passphrase into a fixed-lengt h encryption key" .STR "\nThe longer the passphrase, the more \"randomness\" it contain s and the harder to guess. English text is typically only 1.3 bi ts of randomness per character." .TXT AT (550,6706) RECOLOR ON PARA <0 0 0 0 1000 0 3 108> V_SPACE <83 333 0> SIZE 240000 L_SPACE 333 TXTXYOFF <0 245> T_PNTS (0,245)(0,0)(8880,0)(8880,734)(0,734)(0,245)(8880,245) .STR L_SPACE 444 "http://www.cranfield.ac.uk/docs/email/pgp/pgp-attack-faq.txt \n http://www.schneier.com/paper-personal-entropy.html" END PICTURE NOTES .GRP BACKFILL <34 2 5 1000 0 0 0> PARA <0 0 0 0 1000 1 0 111> V_SPACE <0 250 0> SIZE 180000 L_SPACE 250 MARGINS <125 125 250 62> .TMP AT (250,250) RECOLOR ON TEMPLATE_FLAGS <5 14 0 0> T_POS <250 250 7249 4875> .VOID .TMP AT (250,5125) RECOLOR ON TEMPLATE_FLAGS <6 15 0 0> T_POS <250 5125 7249 9749> .VOID END .GRP END NOTES SLIDE_INFO SLIDE_STYLE <0 -1 1> LAYOUT_ID <0 1 2 3 3> END SLIDE_INFO PICTURE .TMP AT (105,85) RECOLOR ON TEMPLATE_FLAGS <1 1 0 0> T_POS <105 85 9892 1504> .TXT AT (969,203) RECOLOR ON TEMPLATED ON BACKFILL <7 7 0 0 0 0 0> V_SPACE <0 611 0> SIZE 440000 BOLD ON HOR_JUST CENTER L_SPACE 611 MARGINS <0 0 0 0> TXTXYOFF <-26 448> T_PNTS (-3,446)(-3,-2)(7967,-2)(7967,1188)(-3,1188)(-3,446)(7967,446) .STR "Generating encryption keys\nfor symmetric ciphers" .GRP BACKFILL <34 2 5 1000 0 0 0> V_SPACE <0 250 0> SIZE 180000 BOLD OFF HOR_JUST LEFT L_SPACE 250 MARGINS <125 125 250 62> .ELL AT (4498,3250) RECOLOR ON BACKFILL <12 2 5 1000 0 0 0> PARA <0 0 0 0 1000 34 0 111> PNTS (0,0)(500,0)(500,500)(0,500)(0,0) .LINE AT (4578,3323) RECOLOR ON BACKFILL <34 2 5 1000 0 0 0> LINEFILL <1 21 5 1000 0 0 0> THICKNESS 42 PNTS (0,354)(347,0) .LINE AT (4585,3336) RECOLOR ON PNTS (0,0)(340,341) END .GRP .LINE AT (4999,3501) RECOLOR ON LINEFILL <21 21 5 1000 0 0 0> THICKNESS 56 R_ARROW 1 PNTS (0,0)(1000,0) .LINE AT (3499,3501) RECOLOR ON PNTS (0,0)(1000,0) .TXT AT (1631,3021) RECOLOR ON BACKFILL <20 20 5 1000 0 0 0> THICKNESS 0 R_ARROW 0 V_SPACE <0 333 0> SIZE 240000 HOR_JUST CENTER L_SPACE 333 MARGINS <0 0 0 0> TXTXYOFF <-28 238> T_PNTS (0,238)(0,0)(1716,0)(1716,909)(0,909)(0,238)(1716,238) H_SPACE 0 .STR L_SPACE 250 "Passphrase\nentered by\nuser" .TXT AT (6230,3168) RECOLOR ON V_SPACE <0 417 0> SIZE 300000 L_SPACE 417 TXTXYOFF <-39 298> T_PNTS (0,298)(0,0)(1223,0)(1223,807)(0,807)(0,298)(1223,298) .STR L_SPACE 250 "128-bit\nkey" .TXT AT (4366,3821) RECOLOR ON V_SPACE <0 333 0> SIZE 240000 BOLD ON L_SPACE 333 TXTXYOFF <1 238> T_PNTS (0,238)(0,0)(753,0)(753,576)(0,576)(0,238)(753,238) .STR L_SPACE 250 "MD5\nhash" .TXT AT (2062,5910) RECOLOR ON V_SPACE <0 417 0> SIZE 300000 BOLD OFF L_SPACE 417 TXTXYOFF <-31 298> T_PNTS (0,298)(0,0)(5600,0)(5600,807)(0,807)(0,298)(5600,298) .STR L_SPACE 250 "Every passphrase generates a\ndifferent 128-bit key" END PICTURE NOTES .GRP BACKFILL <34 2 5 1000 0 0 0> THICKNESS 1 PARA <0 0 0 0 1000 1 0 111> V_SPACE <0 250 0> SIZE 180000 HOR_JUST LEFT MARGINS <125 125 250 62> .TMP AT (250,250) RECOLOR ON TEMPLATE_FLAGS <5 14 0 0> T_POS <250 250 7249 4875> .VOID .TMP AT (250,5125) RECOLOR ON TEMPLATE_FLAGS <6 15 0 0> T_POS <250 5125 7249 9749> .VOID END .GRP END NOTES SLIDE_INFO SLIDE_STYLE <0 -1 1> LAYOUT_ID <1 12 12 12 12> END SLIDE_INFO PICTURE .TMP AT (105,85) RECOLOR ON TEMPLATE_FLAGS <1 0 0 0> T_POS <105 85 9892 1504> .TXT AT (1010,237) RECOLOR ON TEMPLATED ON BACKFILL <7 7 0 0 0 0 0> V_SPACE <0 611 0> SIZE 440000 BOLD ON HOR_JUST CENTER L_SPACE 611 MARGINS <0 0 0 0> TXTXYOFF <1 437> T_PNTS (-2,435)(-2,-2)(7932,-2)(7932,1177)(-2,1177)(-2,435)(7932,435) H_SPACE 9788 .STR "Example:\nGPG with symmetric cipher" .TXT AT (251,1751) RECOLOR ON BACKFILL <20 20 5 1000 0 0 0> THICKNESS 0 PARA <0 0 0 0 1000 34 0 111> V_SPACE <0 333 0> FONT 5 SIZE 240000 HOR_JUST LEFT L_SPACE 333 MARGINS <166 166 333 83> TXTXYOFF <0 0> PNTS (0,0)(9497,0)(9497,4749)(0,4749)(0,0) H_SPACE 0 .STR BOLD OFF L_SPACE 250 MARGINS <125 125 250 62> "# " .STR BOLD ON L_SPACE 333 MARGINS <166 166 333 83> "vi foobar.txt" .STR BOLD OFF "\n# " .STR BOLD ON "gpg -c foobar.txt" .STR BOLD OFF "\nEnter passphrase: " .STR BOLD ON "ding/dong 479 fruitbat" .STR BOLD OFF "\nRepeat passphrase: " .STR BOLD ON "ding/dong 479 fruitbat" .STR BOLD OFF "\n# " .STR BOLD ON "ls foobar.txt* " .STR BOLD OFF "\nfoobar.txt foobar.txt.gpg \n# " .STR BOLD ON "rm foobar.txt" .STR BOLD OFF " \nrm: remove regular file `foobar.txt'? " .STR BOLD ON "y" .STR BOLD OFF " \n\n# " .STR BOLD ON "gpg foobar.txt.gpg" .STR BOLD OFF "\ngpg: CAST5 encrypted data \nEnter passphrase: " .STR BOLD ON "ding/dong 479 fruitbat" .STR BOLD OFF "\n# " .STR BOLD ON "cat foobar.txt" .TXT AT (580,6707) RECOLOR ON BACKFILL <20 20 0 0 0 0 0> THICKNESS 1 PARA <0 0 0 0 1000 0 3 108> V_SPACE <83 333 0> FONT 2 BOLD OFF MARGINS <0 0 0 0> TXTXYOFF <-33 241> T_PNTS (0,241)(0,0)(6494,0)(6494,314)(0,314)(0,241)(6494,241) H_SPACE 9788 .STR L_SPACE 444 "(\"gpg --version\" shows the ciphers available)" END PICTURE NOTES .GRP BACKFILL <34 2 5 1000 0 0 0> PARA <0 0 0 0 1000 1 0 111> V_SPACE <0 250 0> SIZE 180000 L_SPACE 250 MARGINS <125 125 250 62> .TMP AT (250,250) RECOLOR ON TEMPLATE_FLAGS <5 14 0 0> T_POS <250 250 7249 4875> .VOID .TMP AT (250,5125) RECOLOR ON TEMPLATE_FLAGS <6 15 0 0> T_POS <250 5125 7249 9749> .VOID END .GRP END NOTES SLIDE_INFO SLIDE_STYLE <0 -1 1> LAYOUT_ID <1 2 12 12 12> END SLIDE_INFO PICTURE .TMP AT (105,85) RECOLOR ON TEMPLATE_FLAGS <1 0 0 0> T_POS <105 85 9892 1504> .TXT AT (1680,205) RECOLOR ON TEMPLATED ON BACKFILL <7 7 0 0 0 0 0> V_SPACE <0 611 0> SIZE 440000 BOLD ON HOR_JUST CENTER L_SPACE 611 MARGINS <0 0 0 0> TXTXYOFF <0 448> T_PNTS (-2,447)(-2,-1)(6538,-1)(6538,1188)(-2,1188)(-2,447)(6538,447) .STR "So what use is that?\ne. one-time passwords" .TMP AT (105,1562) RECOLOR ON TEMPLATE_FLAGS <2 3 0 0> T_POS <105 1562 9892 7370> .TXT AT (53,1640) RECOLOR ON TEMPLATED ON BACKFILL <20 20 0 0 0 0 0> PARA <-500 500 -500 1 1000 0 3 108> V_SPACE <333 444 0> SIZE 320000 BOLD OFF HOR_JUST LEFT L_SPACE 444 TXTXYOFF <13 326> T_PNTS (-2,323)(-2,-3)(8526,-3)(8526,2408)(-2,2408)(-2,323)(8526,323) .STR "S/Key (OPIE)" .STR PARA <-500 1000 -500 1 1000 0 3 108> V_SPACE <28 389 0> SIZE 280000 "\n\tGenerates sequence of passwords without storing any secret information on the server!" .STR PARA <-500 500 -500 1 1000 0 3 108> V_SPACE <333 444 0> SIZE 320000 "\nCryptocard" .STR PARA <-500 1000 -500 1 1000 0 3 108> V_SPACE <28 389 0> SIZE 280000 "\n\tPhysical token for challenge-response" END PICTURE NOTES .GRP BACKFILL <34 2 5 1000 0 0 0> PARA <0 0 0 0 1000 1 0 111> V_SPACE <0 250 0> SIZE 180000 L_SPACE 250 MARGINS <125 125 250 62> .TMP AT (250,250) RECOLOR ON TEMPLATE_FLAGS <5 14 0 0> T_POS <250 250 7249 4875> .VOID .TMP AT (250,5125) RECOLOR ON TEMPLATE_FLAGS <6 15 0 0> T_POS <250 5125 7249 9749> .VOID END .GRP END NOTES SLIDE_INFO SLIDE_STYLE <0 -1 1> LAYOUT_ID <1 2 12 12 12> END SLIDE_INFO PICTURE .TMP AT (105,85) RECOLOR ON TEMPLATE_FLAGS <1 0 0 0> T_POS <105 85 9892 1504> .TXT AT (1549,198) RECOLOR ON TEMPLATED ON BACKFILL <7 7 0 0 0 0 0> V_SPACE <0 611 0> SIZE 440000 BOLD ON HOR_JUST CENTER L_SPACE 611 MARGINS <0 0 0 0> TXTXYOFF <1 448> T_PNTS (-1,446)(-1,-2)(6810,-2)(6810,1188)(-1,1188)(-1,446)(6810,446) .STR "So what use is that?\nf. Registering copyright" .TMP AT (105,1562) RECOLOR ON TEMPLATE_FLAGS <2 3 0 0> T_POS <105 1562 9892 7370> .TXT AT (46,1633) RECOLOR ON TEMPLATED ON BACKFILL <20 20 0 0 0 0 0> PARA <-500 500 -500 1 1000 0 3 108> V_SPACE <333 444 0> SIZE 320000 BOLD OFF HOR_JUST LEFT L_SPACE 444 TXTXYOFF <13 322> T_PNTS (-5,320)(-5,-2)(9091,-2)(9091,2436)(-5,2436)(-5,320)(9091,320) .STR "By giving someone the MD5 digest of a document, I can prove tha t I possessed the document at that time, without having to revea l its contents until later\nLots of other uses" END PICTURE NOTES .GRP BACKFILL <34 2 5 1000 0 0 0> PARA <0 0 0 0 1000 1 0 111> V_SPACE <0 250 0> SIZE 180000 L_SPACE 250 MARGINS <125 125 250 62> .TMP AT (250,250) RECOLOR ON TEMPLATE_FLAGS <5 14 0 0> T_POS <250 250 7249 4875> .VOID .TMP AT (250,5125) RECOLOR ON TEMPLATE_FLAGS <6 15 0 0> T_POS <250 5125 7249 9749> .VOID END .GRP END NOTES SLIDE_INFO SLIDE_STYLE <0 -1 1> LAYOUT_ID <0 1 2 3 3> END SLIDE_INFO PICTURE .TMP AT (105,85) RECOLOR ON TEMPLATE_FLAGS <1 1 0 0> T_POS <105 85 9892 1504> .TXT AT (1681,222) RECOLOR ON TEMPLATED ON BACKFILL <7 7 0 0 0 0 0> V_SPACE <0 611 0> SIZE 440000 BOLD ON HOR_JUST CENTER L_SPACE 611 MARGINS <0 0 0 0> TXTXYOFF <-11 437> T_PNTS (-4,435)(-4,-2)(6565,-2)(6565,566)(-4,566)(-4,435)(6565,435) .STR "3. \"Public key\" ciphers" .POL AT (248,2002) RECOLOR ON BACKFILL <34 2 5 1000 0 0 0> PARA <0 0 0 0 1000 34 0 111> V_SPACE <0 250 0> SIZE 180000 BOLD OFF HOR_JUST LEFT L_SPACE 250 MARGINS <125 125 250 62> PNTS (750,0)(0,0)(0,1500)(1000,1500)(1000,250)(750,0) .POL AT (998,2002) RECOLOR ON BACKFILL <34 2 5 500 0 0 0> PNTS (250,250)(0,0)(0,250)(250,250) .POL AT (8747,2002) RECOLOR ON BACKFILL <34 2 5 1000 0 0 0> PNTS (750,0)(0,0)(0,1500)(1000,1500)(1000,250)(750,0) .POL AT (9497,2002) RECOLOR ON BACKFILL <34 2 5 500 0 0 0> PNTS (250,250)(0,0)(0,250)(250,250) .LINE AT (1498,2751) RECOLOR ON BACKFILL <34 2 5 1000 0 0 0> THICKNESS 56 R_ARROW 1 PNTS (0,0)(7000,0) .TXT AT (378,3556) RECOLOR ON BACKFILL <20 20 5 1000 0 0 0> THICKNESS 0 R_ARROW 0 V_SPACE <0 333 0> SIZE 240000 HOR_JUST CENTER L_SPACE 333 MARGINS <0 0 0 0> TXTXYOFF <-11 238> T_PNTS (0,238)(0,0)(703,0)(703,576)(0,576)(0,238)(703,238) H_SPACE 0 .STR L_SPACE 250 "clear\ntext" .TXT AT (8864,3560) RECOLOR ON L_SPACE 333 T_PNTS (0,238)(0,0)(703,0)(703,576)(0,576)(0,238)(703,238) .STR L_SPACE 250 "clear\ntext" .ELL AT (1998,2501) RECOLOR ON BACKFILL <27 2 5 1000 0 0 0> THICKNESS 1 V_SPACE <0 250 0> SIZE 180000 HOR_JUST LEFT MARGINS <125 125 250 62> PNTS (0,0)(500,0)(500,500)(0,500)(0,0) .LINE AT (2248,3001) RECOLOR ON BACKFILL <34 2 5 1000 0 0 0> R_ARROW 1 PNTS (0,750)(0,0) .TXT AT (970,3826) RECOLOR ON BACKFILL <20 20 5 1000 0 0 0> THICKNESS 0 R_ARROW 0 V_SPACE <0 667 0> SIZE 480000 HOR_JUST CENTER L_SPACE 667 MARGINS <0 0 0 0> TXTXYOFF <1 476> T_PNTS (0,476)(0,0)(2500,0)(2500,1352)(0,1352)(0,476)(2500,476) .STR L_SPACE 250 "k" .STR SIZE 360000 SUBSUP <0 100> L_SPACE 667 "1\n(public key)" .LINE AT (2078,2574) RECOLOR ON BACKFILL <34 2 5 1000 0 0 0> LINEFILL <1 21 5 1000 0 0 0> THICKNESS 42 V_SPACE <0 250 0> SIZE 180000 SUBSUP <0 0> HOR_JUST LEFT L_SPACE 250 MARGINS <125 125 250 62> PNTS (0,354)(347,0) .LINE AT (2085,2587) RECOLOR ON PNTS (0,0)(340,341) .ELL AT (7247,2503) RECOLOR ON BACKFILL <27 2 5 1000 0 0 0> LINEFILL <21 21 5 1000 0 0 0> THICKNESS 1 PNTS (0,0)(500,0)(500,500)(0,500)(0,0) .LINE AT (7497,3003) RECOLOR ON BACKFILL <34 2 5 1000 0 0 0> R_ARROW 1 PNTS (0,750)(0,0) .TXT AT (6124,3833) RECOLOR ON BACKFILL <20 20 5 1000 0 0 0> THICKNESS 0 R_ARROW 0 V_SPACE <0 667 0> SIZE 480000 HOR_JUST CENTER L_SPACE 667 MARGINS <0 0 0 0> T_PNTS (0,476)(0,0)(2695,0)(2695,1352)(0,1352)(0,476)(2695,476) .STR L_SPACE 250 "k" .STR SIZE 360000 SUBSUP <0 100> L_SPACE 667 "2\n(private key)" .LINE AT (7327,2576) RECOLOR ON BACKFILL <34 2 5 1000 0 0 0> LINEFILL <1 21 5 1000 0 0 0> THICKNESS 42 V_SPACE <0 250 0> SIZE 180000 SUBSUP <0 0> HOR_JUST LEFT L_SPACE 250 MARGINS <125 125 250 62> PNTS (0,354)(347,0) .LINE AT (7334,2589) RECOLOR ON PNTS (0,0)(340,341) .TXT AT (4250,2811) RECOLOR ON BACKFILL <7 20 5 1000 0 0 0> LINEFILL <21 21 5 1000 0 0 0> THICKNESS 0 V_SPACE <0 333 0> SIZE 240000 BOLD ON HOR_JUST CENTER L_SPACE 333 MARGINS <0 0 0 0> TXTXYOFF <-11 238> T_PNTS (0,238)(0,0)(980,0)(980,576)(0,576)(0,238)(980,238) .STR L_SPACE 250 "cipher\ntext" .TXT AT (1124,5909) RECOLOR ON BACKFILL <20 20 5 1000 0 0 0> V_SPACE <0 417 0> SIZE 300000 BOLD OFF L_SPACE 417 TXTXYOFF <-21 306> T_PNTS (0,306)(0,0)(7619,0)(7619,815)(0,815)(0,306)(7619,306) .STR L_SPACE 250 "One key is used to encrypt the document,\na different key is us ed to decrypt it" END PICTURE NOTES .GRP BACKFILL <34 2 5 1000 0 0 0> THICKNESS 1 PARA <0 0 0 0 1000 1 0 111> V_SPACE <0 250 0> SIZE 180000 HOR_JUST LEFT MARGINS <125 125 250 62> .TMP AT (250,250) RECOLOR ON TEMPLATE_FLAGS <5 14 0 0> T_POS <250 250 7249 4875> .VOID .TMP AT (250,5125) RECOLOR ON TEMPLATE_FLAGS <6 15 0 0> T_POS <250 5125 7249 9749> .VOID END .GRP END NOTES SLIDE_INFO SLIDE_STYLE <0 -1 1> LAYOUT_ID <1 2 12 12 12> END SLIDE_INFO PICTURE .TMP AT (105,85) RECOLOR ON TEMPLATE_FLAGS <1 0 0 0> T_POS <105 85 9892 1504> .TXT AT (1196,225) RECOLOR ON TEMPLATED ON BACKFILL <7 7 0 0 0 0 0> V_SPACE <0 611 0> SIZE 440000 BOLD ON HOR_JUST CENTER L_SPACE 611 MARGINS <0 0 0 0> TXTXYOFF <-44 437> T_PNTS (-2,433)(-2,-4)(7602,-4)(7602,564)(-2,564)(-2,433)(7602,433) H_SPACE 9788 .STR "Public key and Private key" .TMP AT (105,1562) RECOLOR ON TEMPLATE_FLAGS <2 3 0 0> T_POS <105 1562 9892 7370> .TXT AT (43,1638) RECOLOR ON TEMPLATED ON BACKFILL <20 20 0 0 0 0 0> PARA <-500 500 -500 1 1000 0 3 108> V_SPACE <333 444 0> SIZE 320000 BOLD OFF HOR_JUST LEFT L_SPACE 444 TXTXYOFF <13 317> T_PNTS (-6,315)(-6,-2)(9127,-2)(9127,5408)(-6,5408)(-6,315)(9127,315) .STR "The Public key and Private key are mathematically related (gene rated as a pair)" .STR "\nIt is easy to convert the Private key into the Public key. It is not easy to do the reverse." .STR "\nKey distribution problem is solved: you can post your public key anywhere. People can use it to encrypt messages to you, but only the holder of the private key can decrypt them." .STR "\nExamples: RSA, Elgamal (DSA)" END PICTURE NOTES .GRP BACKFILL <34 2 5 1000 0 0 0> PARA <0 0 0 0 1000 1 0 111> V_SPACE <0 250 0> SIZE 180000 L_SPACE 250 MARGINS <125 125 250 62> .TMP AT (250,250) RECOLOR ON TEMPLATE_FLAGS <5 14 0 0> T_POS <250 250 7249 4875> .VOID .TMP AT (250,5125) RECOLOR ON TEMPLATE_FLAGS <6 15 0 0> T_POS <250 5125 7249 9749> .VOID END .GRP END NOTES SLIDE_INFO SLIDE_STYLE <0 -1 1> LAYOUT_ID <0 1 2 3 3> END SLIDE_INFO PICTURE .TMP AT (105,85) RECOLOR ON TEMPLATE_FLAGS <1 1 0 0> T_POS <105 85 9892 1504> .TXT AT (845,212) RECOLOR ON TEMPLATED ON BACKFILL <7 7 0 0 0 0 0> V_SPACE <0 611 0> SIZE 440000 BOLD ON HOR_JUST CENTER L_SPACE 611 MARGINS <0 0 0 0> TXTXYOFF <1 438> T_PNTS (-2,437)(-2,-1)(8203,-1)(8203,1179)(-2,1179)(-2,437)(8203,437) .STR "Use for authentication:\nreverse the roles of the keys" .POL AT (248,2002) RECOLOR ON BACKFILL <34 2 5 1000 0 0 0> PARA <0 0 0 0 1000 34 0 111> V_SPACE <0 250 0> SIZE 180000 BOLD OFF HOR_JUST LEFT L_SPACE 250 MARGINS <125 125 250 62> PNTS (750,0)(0,0)(0,1500)(1000,1500)(1000,250)(750,0) .POL AT (998,2002) RECOLOR ON BACKFILL <34 2 5 500 0 0 0> PNTS (250,250)(0,0)(0,250)(250,250) .POL AT (8747,2002) RECOLOR ON BACKFILL <34 2 5 1000 0 0 0> PNTS (750,0)(0,0)(0,1500)(1000,1500)(1000,250)(750,0) .POL AT (9497,2002) RECOLOR ON BACKFILL <34 2 5 500 0 0 0> PNTS (250,250)(0,0)(0,250)(250,250) .LINE AT (1498,2751) RECOLOR ON BACKFILL <34 2 5 1000 0 0 0> THICKNESS 56 R_ARROW 1 PNTS (0,0)(7000,0) .TXT AT (378,3556) RECOLOR ON BACKFILL <20 20 5 1000 0 0 0> THICKNESS 0 R_ARROW 0 V_SPACE <0 333 0> SIZE 240000 HOR_JUST CENTER L_SPACE 333 MARGINS <0 0 0 0> TXTXYOFF <-11 238> T_PNTS (0,238)(0,0)(703,0)(703,576)(0,576)(0,238)(703,238) H_SPACE 0 .STR L_SPACE 250 "clear\ntext" .TXT AT (8864,3560) RECOLOR ON L_SPACE 333 T_PNTS (0,238)(0,0)(703,0)(703,576)(0,576)(0,238)(703,238) .STR L_SPACE 250 "clear\ntext" .ELL AT (1998,2501) RECOLOR ON BACKFILL <27 2 5 1000 0 0 0> THICKNESS 1 V_SPACE <0 250 0> SIZE 180000 HOR_JUST LEFT MARGINS <125 125 250 62> PNTS (0,0)(500,0)(500,500)(0,500)(0,0) .LINE AT (2248,3001) RECOLOR ON BACKFILL <34 2 5 1000 0 0 0> R_ARROW 1 PNTS (0,750)(0,0) .TXT AT (867,3817) RECOLOR ON BACKFILL <20 20 5 1000 0 0 0> THICKNESS 0 R_ARROW 0 V_SPACE <0 667 0> SIZE 480000 HOR_JUST CENTER L_SPACE 667 MARGINS <0 0 0 0> TXTXYOFF <1 476> T_PNTS (0,476)(0,0)(2695,0)(2695,1352)(0,1352)(0,476)(2695,476) .STR L_SPACE 250 "k" .STR SIZE 360000 SUBSUP <0 100> L_SPACE 667 "2" .STR "\n(private key)" .LINE AT (2078,2574) RECOLOR ON BACKFILL <34 2 5 1000 0 0 0> LINEFILL <1 21 5 1000 0 0 0> THICKNESS 42 V_SPACE <0 250 0> SIZE 180000 SUBSUP <0 0> HOR_JUST LEFT L_SPACE 250 MARGINS <125 125 250 62> PNTS (0,354)(347,0) .LINE AT (2085,2587) RECOLOR ON PNTS (0,0)(340,341) .ELL AT (7247,2503) RECOLOR ON BACKFILL <27 2 5 1000 0 0 0> LINEFILL <21 21 5 1000 0 0 0> THICKNESS 1 PNTS (0,0)(500,0)(500,500)(0,500)(0,0) .LINE AT (7497,3003) RECOLOR ON BACKFILL <34 2 5 1000 0 0 0> R_ARROW 1 PNTS (0,750)(0,0) .TXT AT (6215,3825) RECOLOR ON BACKFILL <20 20 5 1000 0 0 0> THICKNESS 0 R_ARROW 0 V_SPACE <0 667 0> SIZE 480000 HOR_JUST CENTER L_SPACE 667 MARGINS <0 0 0 0> T_PNTS (0,476)(0,0)(2500,0)(2500,1352)(0,1352)(0,476)(2500,476) .STR L_SPACE 250 "k" .STR SIZE 360000 SUBSUP <0 100> L_SPACE 667 "1\n(public key)" .LINE AT (7327,2576) RECOLOR ON BACKFILL <34 2 5 1000 0 0 0> LINEFILL <1 21 5 1000 0 0 0> THICKNESS 42 V_SPACE <0 250 0> SIZE 180000 SUBSUP <0 0> HOR_JUST LEFT L_SPACE 250 MARGINS <125 125 250 62> PNTS (0,354)(347,0) .LINE AT (7334,2589) RECOLOR ON PNTS (0,0)(340,341) .TXT AT (4250,2811) RECOLOR ON BACKFILL <7 20 5 1000 0 0 0> LINEFILL <21 21 5 1000 0 0 0> THICKNESS 0 V_SPACE <0 333 0> SIZE 240000 BOLD ON HOR_JUST CENTER L_SPACE 333 MARGINS <0 0 0 0> TXTXYOFF <-11 238> T_PNTS (0,238)(0,0)(980,0)(980,576)(0,576)(0,238)(980,238) .STR L_SPACE 250 "cipher\ntext" .TXT AT (561,5906) RECOLOR ON BACKFILL <20 20 5 1000 0 0 0> V_SPACE <0 417 0> SIZE 300000 BOLD OFF L_SPACE 417 TXTXYOFF <1 302> T_PNTS (0,302)(0,0)(8727,0)(8727,1228)(0,1228)(0,302)(8727,302) .STR L_SPACE 250 "If you can decrypt the document with the\npublic key, it proves it was written by the\nowner of the private key (and was not ch anged)" END PICTURE NOTES .GRP BACKFILL <34 2 5 1000 0 0 0> THICKNESS 1 PARA <0 0 0 0 1000 1 0 111> V_SPACE <0 250 0> SIZE 180000 HOR_JUST LEFT MARGINS <125 125 250 62> .TMP AT (250,250) RECOLOR ON TEMPLATE_FLAGS <5 14 0 0> T_POS <250 250 7249 4875> .VOID .TMP AT (250,5125) RECOLOR ON TEMPLATE_FLAGS <6 15 0 0> T_POS <250 5125 7249 9749> .VOID END .GRP END NOTES SLIDE_INFO SLIDE_STYLE <0 -1 1> LAYOUT_ID <1 2 12 12 12> END SLIDE_INFO PICTURE .TMP AT (105,85) RECOLOR ON TEMPLATE_FLAGS <1 0 0 0> T_POS <105 85 9892 1504> .TXT AT (3286,225) RECOLOR ON TEMPLATED ON BACKFILL <7 7 0 0 0 0 0> V_SPACE <0 611 0> SIZE 440000 BOLD ON HOR_JUST CENTER L_SPACE 611 MARGINS <0 0 0 0> TXTXYOFF <-46 437> T_PNTS (-1,433)(-1,-4)(3382,-4)(3382,564)(-1,564)(-1,433)(3382,433) H_SPACE 9788 .STR "Key lengths" .TMP AT (105,1562) RECOLOR ON TEMPLATE_FLAGS <2 3 0 0> T_POS <105 1562 9892 7370> .TXT AT (35,1631) RECOLOR ON TEMPLATED ON BACKFILL <20 20 0 0 0 0 0> PARA <-500 500 -500 1 1000 0 3 108> V_SPACE <333 444 0> SIZE 320000 BOLD OFF HOR_JUST LEFT L_SPACE 444 TXTXYOFF <13 317> T_PNTS (-4,314)(-4,-3)(9170,-3)(9170,4520)(-4,4520)(-4,314)(9170,314) .STR "Attacks on public key systems involve mathematical attempts to convert the public key into the private key. This is more effici ent than brute force." .STR "\n512-bit has been broken" .STR "\nRecent developments suggest that 1024-bit keys might not be s ecure for long" .STR "\nRecommend using 2048-bit keys" END PICTURE NOTES .GRP BACKFILL <34 2 5 1000 0 0 0> PARA <0 0 0 0 1000 1 0 111> V_SPACE <0 250 0> SIZE 180000 L_SPACE 250 MARGINS <125 125 250 62> .TMP AT (250,250) RECOLOR ON TEMPLATE_FLAGS <5 14 0 0> T_POS <250 250 7249 4875> .VOID .TMP AT (250,5125) RECOLOR ON TEMPLATE_FLAGS <6 15 0 0> T_POS <250 5125 7249 9749> .VOID END .GRP END NOTES SLIDE_INFO SLIDE_STYLE <0 -1 1> LAYOUT_ID <1 2 12 12 12> END SLIDE_INFO PICTURE .TMP AT (105,85) RECOLOR ON TEMPLATE_FLAGS <1 0 0 0> T_POS <105 85 9892 1504> .TXT AT (1293,225) RECOLOR ON TEMPLATED ON BACKFILL <7 7 0 0 0 0 0> V_SPACE <0 611 0> SIZE 440000 BOLD ON HOR_JUST CENTER L_SPACE 611 MARGINS <0 0 0 0> TXTXYOFF <-46 437> T_PNTS (-3,433)(-3,-4)(7390,-4)(7390,564)(-3,564)(-3,433)(7390,433) .STR "Protecting the private key" .TMP AT (105,1562) RECOLOR ON TEMPLATE_FLAGS <2 3 0 0> T_POS <105 1562 9892 7370> .TXT AT (53,1643) RECOLOR ON TEMPLATED ON BACKFILL <20 20 0 0 0 0 0> PARA <-500 500 -500 1 1000 0 3 108> V_SPACE <333 444 0> SIZE 320000 BOLD OFF HOR_JUST LEFT L_SPACE 444 TXTXYOFF <13 322> T_PNTS (-2,320)(-2,-2)(9174,-2)(9174,5302)(-2,5302)(-2,320)(9174,320) .STR "The security of the private key is paramount: keep it safe!" .STR "\nKeep it on a floppy or a smartcard?" .STR "\nPrefer to keep it " .STR ITALICS ON "encrypted" .STR ITALICS OFF " if on a hard drive" .STR "\nThat means you have to decrypt it (using a passphrase) each t ime you use it" .STR "\nAn attacker would need to steal the file containing the priva te key, AND know or guess the passphrase" END PICTURE NOTES .GRP BACKFILL <34 2 5 1000 0 0 0> PARA <0 0 0 0 1000 1 0 111> V_SPACE <0 250 0> SIZE 180000 L_SPACE 250 MARGINS <125 125 250 62> .TMP AT (250,250) RECOLOR ON TEMPLATE_FLAGS <5 14 0 0> T_POS <250 250 7249 4875> .VOID .TMP AT (250,5125) RECOLOR ON TEMPLATE_FLAGS <6 15 0 0> T_POS <250 5125 7249 9749> .VOID END .GRP END NOTES SLIDE_INFO SLIDE_STYLE <0 -1 1> LAYOUT_ID <0 1 2 3 3> END SLIDE_INFO PICTURE .TMP AT (105,85) RECOLOR ON TEMPLATE_FLAGS <1 1 0 0> T_POS <105 85 9892 1504> .TXT AT (1293,225) RECOLOR ON TEMPLATED ON BACKFILL <7 7 0 0 0 0 0> V_SPACE <0 611 0> SIZE 440000 BOLD ON HOR_JUST CENTER L_SPACE 611 MARGINS <0 0 0 0> TXTXYOFF <-46 437> T_PNTS (-3,433)(-3,-4)(7390,-4)(7390,564)(-3,564)(-3,433)(7390,433) .STR "Protecting the private key" .GRP BACKFILL <34 2 5 1000 0 0 0> V_SPACE <0 250 0> SIZE 180000 BOLD OFF HOR_JUST LEFT L_SPACE 250 MARGINS <125 125 250 62> .ELL AT (3748,5249) RECOLOR ON BACKFILL <12 2 5 1000 0 0 0> PARA <0 0 0 0 1000 34 0 111> PNTS (0,0)(500,0)(500,500)(0,500)(0,0) .LINE AT (3828,5322) RECOLOR ON BACKFILL <34 2 5 1000 0 0 0> LINEFILL <1 21 5 1000 0 0 0> THICKNESS 42 PNTS (0,354)(347,0) .LINE AT (3835,5335) RECOLOR ON PNTS (0,0)(340,341) END .GRP .GRP LINEFILL <21 21 5 1000 0 0 0> THICKNESS 1 PARA <0 0 0 0 1000 1 0 111> .ELL AT (4998,3002) RECOLOR ON BACKFILL <7 2 5 1000 0 0 0> PARA <0 0 0 0 1000 34 0 111> PNTS (0,0)(500,0)(500,500)(0,500)(0,0) .LINE AT (5078,3075) RECOLOR ON BACKFILL <34 2 5 1000 0 0 0> LINEFILL <1 21 5 1000 0 0 0> THICKNESS 42 PNTS (0,354)(347,0) .LINE AT (5085,3088) RECOLOR ON PNTS (0,0)(340,341) END .GRP .RECT AT (2000,2500) RECOLOR ON BACKFILL <2 0 0 0 0 0 0> LINEFILL <21 21 5 1000 0 0 0> THICKNESS 56 STYLE 1 PNTS (0,0)(1998,0)(1998,1500)(0,1500)(0,0) .TXT AT (2171,2606) RECOLOR ON BACKFILL <20 20 5 1000 0 0 0> THICKNESS 0 STYLE 0 V_SPACE <0 500 0> SIZE 240000 HOR_JUST CENTER L_SPACE 333 MARGINS <0 0 0 0> TXTXYOFF <0 357> T_PNTS (0,357)(0,0)(1550,0)(1550,1093)(0,1093)(0,357)(1550,357) H_SPACE 0 .STR SIZE 360000 L_SPACE 250 "k" .STR SIZE 240000 SUBSUP <0 100> L_SPACE 333 "2" .STR V_SPACE <0 333 0> SUBSUP <0 0> "\n(encrypted\non disk)" .LINE AT (3999,3250) RECOLOR ON BACKFILL <34 2 5 1000 0 0 0> THICKNESS 56 R_ARROW 1 V_SPACE <0 250 0> SIZE 180000 HOR_JUST LEFT L_SPACE 250 MARGINS <125 125 250 62> PNTS (0,0)(1000,0) .LINE AT (5499,3250) RECOLOR ON PNTS (0,0)(1250,0) .LINE AT (4249,5500) RECOLOR ON R_ARROW 0 PNTS (0,0)(1000,0) .LINE AT (5249,3500) RECOLOR ON R_ARROW 1 PNTS (0,2000)(0,0) .LINE AT (2749,5500) RECOLOR ON PNTS (0,0)(1000,0) .TXT AT (881,5020) RECOLOR ON BACKFILL <20 20 5 1000 0 0 0> THICKNESS 0 R_ARROW 0 V_SPACE <0 333 0> SIZE 240000 HOR_JUST CENTER L_SPACE 333 MARGINS <0 0 0 0> TXTXYOFF <-28 238> T_PNTS (0,238)(0,0)(1716,0)(1716,909)(0,909)(0,238)(1716,238) .STR L_SPACE 250 "Passphrase\nentered by\nuser" .TXT AT (7017,2684) RECOLOR ON V_SPACE <0 500 0> L_SPACE 333 TXTXYOFF <0 357> T_PNTS (0,357)(0,0)(1005,0)(1005,1030)(0,1030)(0,357)(1005,357) .STR SIZE 360000 L_SPACE 250 "k" .STR SIZE 240000 SUBSUP <0 100> L_SPACE 333 "2" .STR V_SPACE <0 333 0> SUBSUP <0 0> "\nready\nfor use" .TXT AT (3705,5813) RECOLOR ON V_SPACE <0 250 0> SIZE 180000 BOLD ON L_SPACE 250 TXTXYOFF <-14 178> T_PNTS (0,178)(0,0)(551,0)(551,183)(0,183)(0,178)(551,178) .STR "hash" .TXT AT (4598,2374) RECOLOR ON TXTXYOFF <-6 178> T_PNTS (0,178)(0,0)(1235,0)(1235,481)(0,481)(0,178)(1235,178) .STR "symmetric\ncipher" .TXT AT (5369,4346) RECOLOR ON TXTXYOFF <-14 178> T_PNTS (0,178)(0,0)(400,0)(400,233)(0,233)(0,178)(400,178) .STR "key" END PICTURE NOTES .GRP BACKFILL <34 2 5 1000 0 0 0> THICKNESS 1 PARA <0 0 0 0 1000 1 0 111> BOLD OFF HOR_JUST LEFT MARGINS <125 125 250 62> .TMP AT (250,250) RECOLOR ON TEMPLATE_FLAGS <5 14 0 0> T_POS <250 250 7249 4875> .VOID .TMP AT (250,5125) RECOLOR ON TEMPLATE_FLAGS <6 15 0 0> T_POS <250 5125 7249 9749> .VOID END .GRP END NOTES SLIDE_INFO SLIDE_STYLE <0 -1 1> LAYOUT_ID <9 12 12 12 12> END SLIDE_INFO PICTURE .TXT AT (4512,3237) RECOLOR ON BACKFILL <20 20 5 1000 0 0 0> THICKNESS 0 PARA <0 0 0 0 1000 34 0 111> V_SPACE <0 1500 0> SIZE 1080000 BOLD ON L_SPACE 1500 MARGINS <0 0 0 0> TXTXYOFF <-92 1100> T_PNTS (0,1100)(0,0)(723,0)(723,1101)(0,1101)(0,1100)(723,1100) .STR L_SPACE 250 "?" END PICTURE NOTES .GRP BACKFILL <34 2 5 1000 0 0 0> THICKNESS 1 PARA <0 0 0 0 1000 1 0 111> V_SPACE <0 250 0> SIZE 180000 BOLD OFF MARGINS <125 125 250 62> .TMP AT (250,250) RECOLOR ON TEMPLATE_FLAGS <5 14 0 0> T_POS <250 250 7249 4875> .VOID .TMP AT (250,5125) RECOLOR ON TEMPLATE_FLAGS <6 15 0 0> T_POS <250 5125 7249 9749> .VOID END .GRP END NOTES SLIDE_INFO SLIDE_STYLE <0 -1 1> LAYOUT_ID <1 2 12 12 12> END SLIDE_INFO PICTURE .TMP AT (105,85) RECOLOR ON TEMPLATE_FLAGS <1 0 0 0> T_POS <105 85 9892 1504> .TXT AT (732,219) RECOLOR ON TEMPLATED ON BACKFILL <7 7 0 0 0 0 0> V_SPACE <0 611 0> SIZE 440000 BOLD ON HOR_JUST CENTER L_SPACE 611 MARGINS <0 0 0 0> TXTXYOFF <-129 437> T_PNTS (-3,434)(-3,-3)(8686,-3)(8686,1175)(-3,1175)(-3,434)(8686,434) H_SPACE 9788 .STR "Public key cryptosystems are important" .TMP AT (105,1562) RECOLOR ON TEMPLATE_FLAGS <2 3 0 0> T_POS <105 1562 9892 7370> .TXT AT (51,1641) RECOLOR ON TEMPLATED ON BACKFILL <20 20 0 0 0 0 0> PARA <-500 500 -500 1 1000 0 3 108> V_SPACE <333 444 0> SIZE 320000 BOLD OFF HOR_JUST LEFT L_SPACE 444 TXTXYOFF <13 322> T_PNTS (-5,320)(-5,-2)(8153,-2)(8153,2084)(-5,2084)(-5,320)(8153,320) .STR "But they require a lot of computation (expensive in CPU time)" .STR "\nSo we use some tricks to minimise the amount of data which is encrypted" END PICTURE NOTES .GRP BACKFILL <34 2 5 1000 0 0 0> PARA <0 0 0 0 1000 1 0 111> V_SPACE <0 250 0> SIZE 180000 L_SPACE 250 MARGINS <125 125 250 62> .TMP AT (250,250) RECOLOR ON TEMPLATE_FLAGS <5 14 0 0> T_POS <250 250 7249 4875> .VOID .TMP AT (250,5125) RECOLOR ON TEMPLATE_FLAGS <6 15 0 0> T_POS <250 5125 7249 9749> .VOID END .GRP END NOTES SLIDE_INFO SLIDE_STYLE <0 -1 1> LAYOUT_ID <1 2 12 12 12> END SLIDE_INFO PICTURE .TMP AT (105,85) RECOLOR ON TEMPLATE_FLAGS <1 0 0 0> T_POS <105 85 9892 1504> .TXT AT (2397,217) RECOLOR ON TEMPLATED ON BACKFILL <7 7 0 0 0 0 0> V_SPACE <0 611 0> SIZE 440000 BOLD ON HOR_JUST CENTER L_SPACE 611 MARGINS <0 0 0 0> TXTXYOFF <-1 437> T_PNTS (-1,435)(-1,-2)(5078,-2)(5078,566)(-1,566)(-1,435)(5078,435) .STR "When encrypting:" .TMP AT (105,1562) RECOLOR ON TEMPLATE_FLAGS <2 3 0 0> T_POS <105 1562 9892 7370> .TXT AT (53,1653) RECOLOR ON TEMPLATED ON BACKFILL <20 20 0 0 0 0 0> PARA <-500 500 -500 1 1000 0 3 108> V_SPACE <333 444 0> SIZE 320000 BOLD OFF HOR_JUST LEFT L_SPACE 444 TXTXYOFF <13 317> T_PNTS (-2,315)(-2,-2)(9240,-2)(9240,1746)(-2,1746)(-2,315)(9240,315) .STR "Use a symmetric cipher with a random key (the \"session key\"). Use a public key cipher to encrypt the session key and send it along with the encrypted document." .POL AT (249,3752) RECOLOR ON BACKFILL <34 2 5 1000 0 0 0> PARA <0 0 0 0 1000 34 0 111> V_SPACE <0 250 0> SIZE 180000 L_SPACE 250 MARGINS <125 125 250 62> PNTS (750,0)(0,0)(0,1500)(1000,1500)(1000,250)(750,0) .POL AT (999,3752) RECOLOR ON BACKFILL <34 2 5 500 0 0 0> PNTS (250,250)(0,0)(0,250)(250,250) .POL AT (8749,3752) RECOLOR ON BACKFILL <34 2 5 1000 0 0 0> PNTS (750,0)(0,0)(0,1500)(1000,1500)(1000,250)(750,0) .POL AT (9501,3753) RECOLOR ON BACKFILL <34 2 5 500 0 0 0> PNTS (248,252)(0,0)(0,252)(248,252) .LINE AT (2750,5748) RECOLOR ON BACKFILL <34 2 5 1000 0 0 0> THICKNESS 56 PNTS (0,0)(4751,0) .ELL AT (2748,5499) RECOLOR ON BACKFILL <27 2 5 1000 0 0 0> THICKNESS 1 PNTS (0,0)(500,0)(500,500)(0,500)(0,0) .LINE AT (2998,5999) RECOLOR ON BACKFILL <34 2 5 1000 0 0 0> THICKNESS 28 R_ARROW 1 PNTS (0,750)(0,0) .TXT AT (2727,6820) RECOLOR ON BACKFILL <20 20 5 1000 0 0 0> THICKNESS 0 R_ARROW 0 V_SPACE <0 667 0> SIZE 480000 HOR_JUST CENTER L_SPACE 667 MARGINS <0 0 0 0> TXTXYOFF <-41 476> T_PNTS (0,476)(0,0)(464,0)(464,576)(0,576)(0,476)(464,476) H_SPACE 0 .STR L_SPACE 250 "k" .STR SIZE 360000 SUBSUP <0 100> L_SPACE 667 "1" .LINE AT (2828,5572) RECOLOR ON BACKFILL <34 2 5 1000 0 0 0> LINEFILL <1 21 5 1000 0 0 0> THICKNESS 42 V_SPACE <0 250 0> SIZE 180000 SUBSUP <0 0> HOR_JUST LEFT L_SPACE 250 MARGINS <125 125 250 62> PNTS (0,354)(347,0) .LINE AT (2815,5585) RECOLOR ON PNTS (0,0)(340,341) .ELL AT (6752,5500) RECOLOR ON BACKFILL <27 2 5 1000 0 0 0> LINEFILL <21 21 5 1000 0 0 0> THICKNESS 1 PNTS (0,0)(500,0)(500,500)(0,500)(0,0) .LINE AT (7002,6000) RECOLOR ON BACKFILL <34 2 5 1000 0 0 0> THICKNESS 28 R_ARROW 1 PNTS (0,750)(0,0) .TXT AT (6736,6826) RECOLOR ON BACKFILL <20 20 5 1000 0 0 0> THICKNESS 0 R_ARROW 0 V_SPACE <0 667 0> SIZE 480000 HOR_JUST CENTER L_SPACE 667 MARGINS <0 0 0 0> T_PNTS (0,476)(0,0)(546,0)(546,576)(0,576)(0,476)(546,476) .STR L_SPACE 250 "k" .STR SIZE 360000 SUBSUP <0 100> L_SPACE 667 "2" .LINE AT (6832,5573) RECOLOR ON BACKFILL <34 2 5 1000 0 0 0> LINEFILL <1 21 5 1000 0 0 0> THICKNESS 42 V_SPACE <0 250 0> SIZE 180000 SUBSUP <0 0> HOR_JUST LEFT L_SPACE 250 MARGINS <125 125 250 62> PNTS (0,354)(347,0) .LINE AT (6839,5586) RECOLOR ON PNTS (0,0)(340,341) .TXT AT (3785,5798) RECOLOR ON BACKFILL <7 20 5 1000 0 0 0> LINEFILL <21 21 5 1000 0 0 0> THICKNESS 0 V_SPACE <0 333 0> SIZE 240000 BOLD ON HOR_JUST CENTER L_SPACE 333 MARGINS <0 0 0 0> TXTXYOFF <1 238> T_PNTS (0,238)(0,0)(1886,0)(1886,644)(0,644)(0,238)(1886,238) .STR L_SPACE 250 "encrypted\nsession key" .LINE AT (1500,4748) RECOLOR ON BACKFILL <34 2 5 1000 0 0 0> THICKNESS 56 R_ARROW 1 V_SPACE <0 250 0> SIZE 180000 BOLD OFF HOR_JUST LEFT MARGINS <125 125 250 62> PNTS (0,0)(7000,0) .GRP THICKNESS 1 R_ARROW 0 PARA <0 0 0 0 1000 1 0 111> .ELL AT (2000,4498) RECOLOR ON BACKFILL <7 2 5 1000 0 0 0> PARA <0 0 0 0 1000 34 0 111> PNTS (0,0)(500,0)(500,500)(0,500)(0,0) .LINE AT (2080,4571) RECOLOR ON BACKFILL <34 2 5 1000 0 0 0> LINEFILL <1 21 5 1000 0 0 0> THICKNESS 42 PNTS (0,354)(347,0) .LINE AT (2087,4584) RECOLOR ON PNTS (0,0)(340,341) END .GRP .GRP LINEFILL <21 21 5 1000 0 0 0> THICKNESS 1 PARA <0 0 0 0 1000 1 0 111> .ELL AT (7249,4500) RECOLOR ON BACKFILL <7 2 5 1000 0 0 0> PARA <0 0 0 0 1000 34 0 111> PNTS (0,0)(500,0)(500,500)(0,500)(0,0) .LINE AT (7329,4573) RECOLOR ON BACKFILL <34 2 5 1000 0 0 0> LINEFILL <1 21 5 1000 0 0 0> THICKNESS 42 PNTS (0,354)(347,0) .LINE AT (7336,4586) RECOLOR ON PNTS (0,0)(340,341) END .GRP .TXT AT (4225,4806) RECOLOR ON BACKFILL <7 20 5 1000 0 0 0> LINEFILL <21 21 5 1000 0 0 0> THICKNESS 0 V_SPACE <0 333 0> SIZE 240000 BOLD ON HOR_JUST CENTER L_SPACE 333 MARGINS <0 0 0 0> TXTXYOFF <-11 238> T_PNTS (0,238)(0,0)(980,0)(980,576)(0,576)(0,238)(980,238) .STR L_SPACE 250 "cipher\ntext" .LINE AT (7500,5000) RECOLOR ON BACKFILL <34 2 5 1000 0 0 0> THICKNESS 56 R_ARROW 1 V_SPACE <0 250 0> SIZE 180000 BOLD OFF HOR_JUST LEFT MARGINS <125 125 250 62> PNTS (0,750)(0,0) .LINE AT (2000,5750) RECOLOR ON PNTS (0,0)(752,0) .LINE AT (2250,5000) RECOLOR ON PNTS (0,750)(0,0) .TXT AT (206,5459) RECOLOR ON BACKFILL <7 20 5 1000 0 0 0> THICKNESS 0 R_ARROW 0 V_SPACE <0 333 0> SIZE 240000 BOLD ON ITALICS ON HOR_JUST CENTER L_SPACE 333 MARGINS <0 0 0 0> TXTXYOFF <3 238> T_PNTS (0,238)(0,0)(1901,0)(1901,642)(0,642)(0,238)(1901,238) .STR BACKFILL <1 20 5 1000 0 0 0> L_SPACE 250 "random\nsession key" .TXT AT (2426,4936) RECOLOR ON BACKFILL <20 20 5 1000 0 0 0> V_SPACE <0 667 0> SIZE 480000 BOLD OFF ITALICS OFF L_SPACE 667 TXTXYOFF <-31 357> T_PNTS (0,357)(0,0)(370,0)(370,462)(0,462)(0,357)(370,357) .STR V_SPACE <0 500 0> SIZE 360000 L_SPACE 250 "k" .STR SIZE 240000 SUBSUP <0 100> L_SPACE 667 "s" .TXT AT (7684,4950) RECOLOR ON V_SPACE <0 667 0> SIZE 480000 SUBSUP <0 0> T_PNTS (0,357)(0,0)(370,0)(370,462)(0,462)(0,357)(370,357) .STR V_SPACE <0 500 0> SIZE 360000 L_SPACE 250 "k" .STR SIZE 240000 SUBSUP <0 100> L_SPACE 667 "s" .TXT AT (7435,6970) RECOLOR ON V_SPACE <0 250 0> SIZE 180000 SUBSUP <0 0> L_SPACE 250 TXTXYOFF <-24 180> T_PNTS (0,180)(0,0)(867,0)(867,233)(0,233)(0,180)(867,180) .STR "(private)" .TXT AT (3479,6975) RECOLOR ON TXTXYOFF <-23 180> T_PNTS (0,180)(0,0)(769,0)(769,233)(0,233)(0,180)(769,180) .STR "(public)" END PICTURE NOTES .GRP BACKFILL <34 2 5 1000 0 0 0> THICKNESS 1 PARA <0 0 0 0 1000 1 0 111> HOR_JUST LEFT MARGINS <125 125 250 62> .TMP AT (250,250) RECOLOR ON TEMPLATE_FLAGS <5 14 0 0> T_POS <250 250 7249 4875> .VOID .TMP AT (250,5125) RECOLOR ON TEMPLATE_FLAGS <6 15 0 0> T_POS <250 5125 7249 9749> .VOID END .GRP END NOTES SLIDE_INFO SLIDE_STYLE <0 -1 1> LAYOUT_ID <1 2 12 12 12> END SLIDE_INFO PICTURE .TMP AT (105,85) RECOLOR ON TEMPLATE_FLAGS <1 0 0 0> T_POS <105 85 9892 1504> .TXT AT (1886,222) RECOLOR ON TEMPLATED ON BACKFILL <7 7 0 0 0 0 0> V_SPACE <0 611 0> SIZE 440000 BOLD ON HOR_JUST CENTER L_SPACE 611 MARGINS <0 0 0 0> TXTXYOFF <-1 437> T_PNTS (-2,435)(-2,-2)(6123,-2)(6123,566)(-2,566)(-2,435)(6123,435) H_SPACE 9788 .STR "When authenticating:" .TMP AT (105,1562) RECOLOR ON TEMPLATE_FLAGS <2 3 0 0> T_POS <105 1562 9892 7370> .TXT AT (48,1643) RECOLOR ON TEMPLATED ON BACKFILL <20 20 0 0 0 0 0> PARA <-500 500 -500 1 1000 0 3 108> V_SPACE <333 444 0> SIZE 320000 BOLD OFF HOR_JUST LEFT L_SPACE 444 TXTXYOFF <13 322> T_PNTS (-2,320)(-2,-2)(8803,-2)(8803,1307)(-2,1307)(-2,320)(8803,320) .STR "Take a hash of the document and encrypt only that. An encrypted hash is called a \"digital signature\"" .POL AT (249,3251) RECOLOR ON BACKFILL <34 2 5 1000 0 0 0> PARA <0 0 0 0 1000 34 0 111> V_SPACE <0 250 0> SIZE 180000 L_SPACE 250 MARGINS <125 125 250 62> PNTS (750,0)(0,0)(0,1500)(1000,1500)(1000,250)(750,0) .POL AT (999,3251) RECOLOR ON BACKFILL <34 2 5 500 0 0 0> PNTS (250,250)(0,0)(0,250)(250,250) .POL AT (8749,3251) RECOLOR ON BACKFILL <34 2 5 1000 0 0 0> PNTS (750,0)(0,0)(0,1500)(1000,1500)(1000,250)(750,0) .POL AT (9501,3252) RECOLOR ON BACKFILL <34 2 5 500 0 0 0> PNTS (248,252)(0,0)(0,252)(248,252) .LINE AT (2750,5748) RECOLOR ON BACKFILL <34 2 5 1000 0 0 0> THICKNESS 56 R_ARROW 1 PNTS (0,0)(5249,0) .ELL AT (2748,5499) RECOLOR ON BACKFILL <27 2 5 1000 0 0 0> THICKNESS 1 R_ARROW 0 PNTS (0,0)(500,0)(500,500)(0,500)(0,0) .LINE AT (2998,5999) RECOLOR ON BACKFILL <34 2 5 1000 0 0 0> THICKNESS 28 R_ARROW 1 PNTS (0,750)(0,0) .TXT AT (2727,6822) RECOLOR ON BACKFILL <20 20 5 1000 0 0 0> THICKNESS 0 R_ARROW 0 V_SPACE <0 667 0> SIZE 480000 HOR_JUST CENTER L_SPACE 667 MARGINS <0 0 0 0> TXTXYOFF <-41 476> T_PNTS (0,476)(0,0)(546,0)(546,576)(0,576)(0,476)(546,476) H_SPACE 0 .STR L_SPACE 250 "k" .STR SIZE 360000 SUBSUP <0 100> L_SPACE 667 "2" .LINE AT (2828,5572) RECOLOR ON BACKFILL <34 2 5 1000 0 0 0> LINEFILL <1 21 5 1000 0 0 0> THICKNESS 42 V_SPACE <0 250 0> SIZE 180000 SUBSUP <0 0> HOR_JUST LEFT L_SPACE 250 MARGINS <125 125 250 62> PNTS (0,354)(347,0) .LINE AT (2835,5585) RECOLOR ON PNTS (0,0)(340,341) .ELL AT (6752,5500) RECOLOR ON BACKFILL <27 2 5 1000 0 0 0> LINEFILL <21 21 5 1000 0 0 0> THICKNESS 1 PNTS (0,0)(500,0)(500,500)(0,500)(0,0) .LINE AT (7002,6000) RECOLOR ON BACKFILL <34 2 5 1000 0 0 0> THICKNESS 28 R_ARROW 1 PNTS (0,750)(0,0) .TXT AT (6736,6825) RECOLOR ON BACKFILL <20 20 5 1000 0 0 0> THICKNESS 0 R_ARROW 0 V_SPACE <0 667 0> SIZE 480000 HOR_JUST CENTER L_SPACE 667 MARGINS <0 0 0 0> T_PNTS (0,476)(0,0)(464,0)(464,576)(0,576)(0,476)(464,476) .STR L_SPACE 250 "k" .STR SIZE 360000 SUBSUP <0 100> L_SPACE 667 "1" .LINE AT (6832,5573) RECOLOR ON BACKFILL <34 2 5 1000 0 0 0> LINEFILL <1 21 5 1000 0 0 0> THICKNESS 42 V_SPACE <0 250 0> SIZE 180000 SUBSUP <0 0> HOR_JUST LEFT L_SPACE 250 MARGINS <125 125 250 62> PNTS (0,354)(347,0) .LINE AT (6839,5586) RECOLOR ON PNTS (0,0)(340,341) .TXT AT (4075,5836) RECOLOR ON BACKFILL <7 20 5 1000 0 0 0> LINEFILL <21 21 5 1000 0 0 0> THICKNESS 0 V_SPACE <0 333 0> SIZE 240000 BOLD ON HOR_JUST CENTER L_SPACE 333 MARGINS <0 0 0 0> TXTXYOFF <0 238> T_PNTS (0,238)(0,0)(1484,0)(1484,644)(0,644)(0,238)(1484,238) .STR L_SPACE 250 "digital\nsignature" .LINE AT (1502,4001) RECOLOR ON BACKFILL <34 2 5 1000 0 0 0> THICKNESS 56 R_ARROW 1 V_SPACE <0 250 0> SIZE 180000 BOLD OFF HOR_JUST LEFT MARGINS <125 125 250 62> PNTS (0,0)(7000,0) .LINE AT (2249,5750) RECOLOR ON PNTS (0,0)(502,0) .LINE AT (2250,5000) RECOLOR ON R_ARROW 0 PNTS (0,750)(0,0) .LINE AT (2250,4000) RECOLOR ON PNTS (0,0)(0,500) .GRP THICKNESS 1 PARA <0 0 0 0 1000 1 0 111> .ELL AT (2000,4498) RECOLOR ON BACKFILL <12 2 5 1000 0 0 0> PARA <0 0 0 0 1000 34 0 111> PNTS (0,0)(500,0)(500,500)(0,500)(0,0) .LINE AT (2080,4571) RECOLOR ON BACKFILL <34 2 5 1000 0 0 0> LINEFILL <1 21 5 1000 0 0 0> THICKNESS 42 PNTS (0,354)(347,0) .LINE AT (2087,4584) RECOLOR ON PNTS (0,0)(340,341) END .GRP .LINE AT (7498,5498) RECOLOR ON LINEFILL <21 21 5 1000 0 0 0> THICKNESS 56 R_ARROW 1 PNTS (0,0)(502,0) .LINE AT (7499,5000) RECOLOR ON R_ARROW 0 PNTS (0,496)(0,0) .LINE AT (7499,4000) RECOLOR ON PNTS (0,0)(0,500) .GRP THICKNESS 1 PARA <0 0 0 0 1000 1 0 111> .ELL AT (7249,4498) RECOLOR ON BACKFILL <12 2 5 1000 0 0 0> PARA <0 0 0 0 1000 34 0 111> PNTS (0,0)(500,0)(500,500)(0,500)(0,0) .LINE AT (7329,4571) RECOLOR ON BACKFILL <34 2 5 1000 0 0 0> LINEFILL <1 21 5 1000 0 0 0> THICKNESS 42 PNTS (0,354)(347,0) .LINE AT (7336,4584) RECOLOR ON PNTS (0,0)(340,341) END .GRP .TXT AT (8130,5471) RECOLOR ON BACKFILL <7 20 5 1000 0 0 0> LINEFILL <21 21 5 1000 0 0 0> THICKNESS 0 V_SPACE <0 333 0> SIZE 240000 BOLD ON HOR_JUST CENTER L_SPACE 333 MARGINS <0 0 0 0> TXTXYOFF <-13 245> T_PNTS (0,245)(0,0)(1670,0)(1670,252)(0,252)(0,245)(1670,245) .STR L_SPACE 250 "COMPARE" .TXT AT (2589,4636) RECOLOR ON BACKFILL <20 20 5 1000 0 0 0> V_SPACE <0 250 0> SIZE 180000 TXTXYOFF <-14 178> T_PNTS (0,178)(0,0)(551,0)(551,183)(0,183)(0,178)(551,178) .STR "hash" .TXT AT (7834,4621) RECOLOR ON T_PNTS (0,178)(0,0)(551,0)(551,183)(0,183)(0,178)(551,178) .STR "hash" .TXT AT (7474,6967) RECOLOR ON BOLD OFF TXTXYOFF <-23 180> T_PNTS (0,180)(0,0)(769,0)(769,233)(0,233)(0,180)(769,180) .STR "(public)" .TXT AT (3435,6970) RECOLOR ON TXTXYOFF <-24 180> T_PNTS (0,180)(0,0)(867,0)(867,233)(0,233)(0,180)(867,180) .STR "(private)" END PICTURE NOTES .GRP BACKFILL <34 2 5 1000 0 0 0> THICKNESS 1 PARA <0 0 0 0 1000 1 0 111> HOR_JUST LEFT MARGINS <125 125 250 62> .TMP AT (250,250) RECOLOR ON TEMPLATE_FLAGS <5 14 0 0> T_POS <250 250 7249 4875> .VOID .TMP AT (250,5125) RECOLOR ON TEMPLATE_FLAGS <6 15 0 0> T_POS <250 5125 7249 9749> .VOID END .GRP END NOTES SLIDE_INFO SLIDE_STYLE <0 -1 1> LAYOUT_ID <1 2 12 12 12> END SLIDE_INFO PICTURE .TMP AT (105,85) RECOLOR ON TEMPLATE_FLAGS <1 0 0 0> T_POS <105 85 9892 1504> .TXT AT (779,213) RECOLOR ON TEMPLATED ON BACKFILL <7 7 0 0 0 0 0> V_SPACE <0 611 0> SIZE 440000 BOLD ON HOR_JUST CENTER L_SPACE 611 MARGINS <0 0 0 0> TXTXYOFF <-129 448> T_PNTS (-2,445)(-2,-3)(8611,-3)(8611,1066)(-2,1066)(-2,445)(8611,445) H_SPACE 9788 .STR "Digital Signatures have many uses..." .TMP AT (105,1562) RECOLOR ON TEMPLATE_FLAGS <2 3 0 0> T_POS <105 1562 9892 7370> .TXT AT (58,1653) RECOLOR ON TEMPLATED ON BACKFILL <20 20 0 0 0 0 0> PARA <-500 500 -500 1 1000 0 3 108> V_SPACE <333 444 0> SIZE 320000 BOLD OFF HOR_JUST LEFT L_SPACE 444 TXTXYOFF <13 317> T_PNTS (-6,315)(-6,-2)(9200,-2)(9200,5799)(-6,5799)(-6,315)(9200,315) .STR "E-commerce. An instruction to your bank to transfer money can b e authenticated with a digital signature." .STR PARA <-500 1000 -500 1 1000 0 3 108> V_SPACE <28 389 0> SIZE 280000 "\n\tLegislative regimes are slow to catch up" .STR PARA <-500 500 -500 1 1000 0 3 108> V_SPACE <333 444 0> SIZE 320000 "\nA trusted third party can issue declarations such as \"the ho lder of this key is a person who is legally known as Alice Hacke r\"" .STR PARA <-500 1000 -500 1 1000 0 3 108> V_SPACE <28 389 0> SIZE 280000 "\n\tlike a passport binds your identity to your face" .STR PARA <-500 500 -500 1 1000 0 3 108> V_SPACE <333 444 0> SIZE 320000 "\nSuch a declaration is called a \"certificate\"" .STR "\nYou only need the third-party's public key to check the signa ture" END PICTURE NOTES .GRP BACKFILL <34 2 5 1000 0 0 0> PARA <0 0 0 0 1000 1 0 111> V_SPACE <0 250 0> SIZE 180000 L_SPACE 250 MARGINS <125 125 250 62> .TMP AT (250,250) RECOLOR ON TEMPLATE_FLAGS <5 14 0 0> T_POS <250 250 7249 4875> .VOID .TMP AT (250,5125) RECOLOR ON TEMPLATE_FLAGS <6 15 0 0> T_POS <250 5125 7249 9749> .VOID END .GRP END NOTES SLIDE_INFO SLIDE_STYLE <0 -1 1> LAYOUT_ID <1 2 12 12 12> END SLIDE_INFO PICTURE .TMP AT (105,85) RECOLOR ON TEMPLATE_FLAGS <1 0 0 0> T_POS <105 85 9892 1504> .TXT AT (531,203) RECOLOR ON TEMPLATED ON BACKFILL <7 7 0 0 0 0 0> V_SPACE <0 611 0> SIZE 440000 BOLD ON HOR_JUST CENTER L_SPACE 611 MARGINS <0 0 0 0> TXTXYOFF <-24 448> T_PNTS (-1,446)(-1,-2)(8875,-2)(8875,577)(-1,577)(-1,446)(8875,446) .STR "Communicating with strangers" .TMP AT (105,1562) RECOLOR ON TEMPLATE_FLAGS <2 3 0 0> T_POS <105 1562 9892 7370> .TXT AT (25,1610) RECOLOR ON TEMPLATED ON BACKFILL <20 20 0 0 0 0 0> PARA <-500 500 -500 1 1000 0 3 108> V_SPACE <333 444 0> SIZE 320000 BOLD OFF HOR_JUST LEFT L_SPACE 444 TXTXYOFF <13 326> T_PNTS (-6,323)(-6,-3)(9231,-3)(9231,3741)(-6,3741)(-6,323)(9231,323) .STR "Often we want to communicate securely with a remote party we ha ve no prior knowledge of, e.g. a website\nWe can agree on an enc ryption key in such a way that a passive observer cannot see it" .STR PARA <-500 1000 -500 1 1000 0 3 108> V_SPACE <28 389 0> SIZE 280000 "\ne.g. Diffie-Hellman key exchange" .STR "\n\t\tor just send me your public key and I'll send you back an encrypted session key" .LINE AT (1000,6499) RECOLOR ON BACKFILL <34 2 5 1000 0 0 0> THICKNESS 56 R_ARROW 1 PARA <0 0 0 0 1000 34 0 111> V_SPACE <0 250 0> SIZE 180000 L_SPACE 250 MARGINS <125 125 250 62> PNTS (0,0)(7750,0) .GRP THICKNESS 1 R_ARROW 0 PARA <0 0 0 0 1000 1 0 111> .ELL AT (1500,6249) RECOLOR ON BACKFILL <7 2 5 1000 0 0 0> PARA <0 0 0 0 1000 34 0 111> PNTS (0,0)(500,0)(500,500)(0,500)(0,0) .LINE AT (1580,6322) RECOLOR ON BACKFILL <34 2 5 1000 0 0 0> LINEFILL <1 21 5 1000 0 0 0> THICKNESS 42 PNTS (0,354)(347,0) .LINE AT (1587,6335) RECOLOR ON PNTS (0,0)(340,341) END .GRP .GRP LINEFILL <21 21 5 1000 0 0 0> THICKNESS 1 PARA <0 0 0 0 1000 1 0 111> .ELL AT (7749,6249) RECOLOR ON BACKFILL <7 2 5 1000 0 0 0> PARA <0 0 0 0 1000 34 0 111> PNTS (0,0)(500,0)(500,500)(0,500)(0,0) .LINE AT (7829,6322) RECOLOR ON BACKFILL <34 2 5 1000 0 0 0> LINEFILL <1 21 5 1000 0 0 0> THICKNESS 42 PNTS (0,354)(347,0) .LINE AT (7836,6335) RECOLOR ON PNTS (0,0)(340,341) END .GRP .POL AT (1750,5998) RECOLOR ON LINEFILL <21 21 5 1000 0 0 0> THICKNESS 1 L_ARROW 1 R_ARROW 1 PNTS (0,0)(6250,0) .TXT AT (4442,6045) RECOLOR ON BACKFILL <20 20 5 1000 0 0 0> THICKNESS 0 L_ARROW 0 R_ARROW 0 MARGINS <0 0 0 0> TXTXYOFF <-11 178> T_PNTS (0,178)(0,0)(1069,0)(1069,233)(0,233)(0,178)(1069,178) H_SPACE 0 .STR "encrypted" .ELL AT (315,5818) RECOLOR ON BACKFILL <34 2 0 0 0 0 0> THICKNESS 1 MARGINS <125 125 250 62> PNTS (0,0)(377,0)(377,432)(0,432)(0,0) .LINE AT (500,6250) RECOLOR ON BACKFILL <34 2 5 1000 0 0 0> PNTS (0,0)(0,500) .LINE AT (250,6750) RECOLOR ON PNTS (250,0)(0,250) .LINE AT (500,6750) RECOLOR ON PNTS (0,0)(250,250) .LINE AT (250,6500) RECOLOR ON PNTS (0,0)(500,0) .GRP BACKFILL <1 0 0 0 0 0 0> LINEFILL <1 2 5 1000 0 0 0> SHADOW <6 0 15 15> PARA <0 0 0 0 1000 1 0 111> FONT 0 .POL AT (9128,6773) BACKFILL <48 0 0 5 0 0 0> THICKNESS 0 PNTS (512,185)(512,0)(0,0)(0,185)(512,185) .POL AT (9630,6771) BACKFILL <1 0 0 5 0 0 0> PNTS (2,4)(0,2)(0,187)(4,187)(4,2)(2,0)(4,2)(4,0)(2,0)(2,4) .POL AT (9138,6771) PNTS (4,2)(3,4)(494,4)(494,0)(3,0)(0,2)(3,0)(0,0)(0,2)(4,2) .POL AT (9138,6773) PNTS (3,183)(4,185)(4,0)(0,0)(0,185)(3,187)(0,185)(0,187)(3,187) (3,183) .POL AT (9141,6956) BACKFILL <49 0 0 5 0 0 0> PNTS (489,2)(491,0)(0,0)(0,4)(491,4)(493,2)(491,4)(493,4)(493,2) (489,2) .POL AT (9130,6625) BACKFILL <48 0 0 5 0 0 0> PNTS (0,0)(7,50)(507,50)(513,0)(0,0) .POL AT (9128,6625) BACKFILL <1 0 0 5 0 0 0> PNTS (9,49)(10,50)(3,0)(0,0)(7,50)(9,53)(7,50)(7,53)(9,53)(9,49) .POL AT (9137,6674) PNTS (498,1)(500,0)(0,0)(0,4)(500,4)(502,1)(500,4)(502,4)(502,1) (498,1) .POL AT (9635,6623) PNTS (8,3)(7,2)(0,52)(4,52)(10,2)(8,0)(10,2)(11,0)(8,0)(8,3) .POL AT (9128,6623) PNTS (3,2)(2,3)(515,3)(515,0)(2,0)(0,2)(2,0)(0,0)(0,2)(3,2) .POL AT (9596,6634) PNTS (2,4)(0,1)(0,31)(4,31)(4,1)(2,0)(4,1)(4,0)(2,0)(2,4) .POL AT (9538,6634) PNTS (4,1)(3,4)(60,4)(60,0)(3,0)(0,1)(3,0)(0,0)(0,1)(4,1) .POL AT (9538,6635) PNTS (3,28)(4,30)(4,0)(0,0)(0,30)(3,32)(0,30)(0,32)(3,32)(3,28) .POL AT (9541,6663) PNTS (55,2)(57,0)(0,0)(0,4)(57,4)(59,2)(57,4)(59,4)(59,2)(55,2) .POL AT (9541,6637) BACKFILL <50 0 0 5 0 0 0> PNTS (19,27)(19,0)(0,0)(0,27)(19,27) .POL AT (9557,6635) BACKFILL <1 0 0 5 0 0 0> PNTS (3,4)(0,2)(0,29)(4,29)(4,2)(3,0)(4,2)(4,0)(3,0)(3,4) .POL AT (9540,6635) PNTS (4,2)(1,4)(20,4)(20,0)(1,0)(0,2)(1,0)(0,0)(0,2)(4,2) .POL AT (9540,6637) PNTS (1,24)(4,27)(4,0)(0,0)(0,27)(1,28)(0,27)(0,28)(1,28)(1,24) .POL AT (9541,6661) PNTS (16,3)(19,0)(0,0)(0,4)(19,4)(20,3)(19,4)(20,4)(20,3)(16,3) .POL AT (9237,6675) BACKFILL <51 0 0 5 0 0 0> PNTS (45,24)(0,0)(299,0)(254,24)(45,24) .POL AT (9230,6674) BACKFILL <1 0 0 5 0 0 0> PNTS (7,0)(6,3)(52,27)(53,24)(8,0)(7,4)(7,0)(0,0)(6,3)(7,0) .POL AT (9237,6674) PNTS (300,3)(299,0)(0,0)(0,4)(299,4)(298,0)(300,3)(307,0)(299,0) (300,3) .POL AT (9490,6674) PNTS (1,28)(2,27)(47,3)(45,0)(0,24)(1,24)(1,28)(2,28)(2,27)(1,28) .POL AT (9282,6698) PNTS (0,3)(0,4)(209,4)(209,0)(0,0)(1,0)(0,3)(0,4)(0,4)(0,3) .POL AT (9269,6699) BACKFILL <48 0 0 5 0 0 0> PNTS (13,0)(0,25)(236,25)(222,0)(13,0) .POL AT (9266,6698) BACKFILL <1 0 0 5 0 0 0> PNTS (3,23)(4,26)(18,2)(15,0)(1,25)(3,27)(1,25)(0,27)(3,27)(3,23) .POL AT (9269,6721) PNTS (234,3)(236,0)(0,0)(0,4)(236,4)(238,2)(236,4)(239,4)(238,2) (234,3) .POL AT (9489,6698) PNTS (2,4)(0,2)(14,26)(18,25)(3,0)(2,0)(3,0)(3,0)(2,0)(2,4) .POL AT (9281,6698) PNTS (3,2)(1,4)(210,4)(210,0)(1,0)(0,0)(1,0)(1,0)(0,0)(3,2) .POL AT (9049,6623) PNTS (32,24)(39,0)(0,0)(6,24)(32,24) .POL AT (9079,6621) PNTS (9,4)(7,2)(0,26)(3,27)(10,2)(9,0)(10,2)(11,0)(9,0)(9,4) .POL AT (9047,6621) PNTS (4,2)(2,4)(41,4)(41,0)(2,0)(1,2)(2,0)(0,0)(1,2)(4,2) .POL AT (9048,6623) PNTS (7,22)(9,24)(3,0)(0,0)(6,25)(7,26)(6,25)(7,26)(7,26)(7,22) .POL AT (9055,6645) PNTS (24,2)(26,0)(0,0)(0,4)(26,4)(27,3)(26,4)(27,4)(27,3)(24,2) .POL AT (9686,6623) BACKFILL <49 0 0 5 0 0 0> PNTS (6,24)(0,0)(39,0)(32,24)(6,24) .POL AT (9684,6621) BACKFILL <1 0 0 5 0 0 0> PNTS (2,0)(0,2)(7,27)(10,26)(4,2)(2,4)(2,0)(0,0)(0,2)(2,0) .POL AT (9686,6621) PNTS (40,2)(39,0)(0,0)(0,4)(39,4)(37,2)(40,2)(41,0)(39,0)(40,2) .POL AT (9717,6623) PNTS (1,26)(3,25)(9,0)(6,0)(0,24)(1,22)(1,26)(2,26)(3,25)(1,26) .POL AT (9691,6645) PNTS (0,3)(1,4)(27,4)(27,0)(1,0)(3,2)(0,3)(1,4)(1,4)(0,3) .POL AT (9130,6724) BACKFILL <48 0 0 5 0 0 0> PNTS (5,57)(3,56)(1,55)(1,53)(0,51)(0,5)(1,3)(1,1)(3,0)(5,0)(508,0) (510,0)(512,1)(513,3)(513,5)(513,51)(513,53)(512,55)(510,56) (508,57)(5,57) .POL AT (9128,6775) BACKFILL <1 0 0 5 0 0 0> PNTS (0,0)(1,0)(1,2)(3,5)(5,6)(7,7)(7,3)(6,3)(5,2)(4,2)(4,0)(4,0) (0,0) .POL AT (9128,6729) PNTS (0,0)(1,0)(0,46)(4,46)(4,0)(4,0)(0,0) .POL AT (9128,6721) PNTS (7,0)(8,0)(5,1)(3,3)(1,5)(0,8)(4,8)(4,6)(5,5)(6,4)(7,4)(7,4) (7,0) .POL AT (9135,6721) PNTS (503,0)(504,0)(0,0)(0,4)(503,4)(503,4)(503,0) .POL AT (9638,6721) PNTS (8,8)(9,8)(7,5)(5,3)(3,1)(0,0)(0,4)(2,4)(3,5)(4,6)(4,8)(4,8) (8,8) .POL AT (9642,6729) PNTS (4,46)(5,46)(4,0)(0,0)(0,46)(0,46)(4,46) .POL AT (9638,6775) PNTS (0,7)(1,7)(3,6)(5,5)(7,2)(8,0)(4,0)(4,2)(3,2)(2,3)(0,3)(0,3) (0,7) .POL AT (9135,6778) PNTS (0,4)(1,4)(503,4)(503,0)(0,0)(0,0)(0,4) .POL AT (9128,6915) PNTS (0,0)(1,0)(1,5)(2,10)(4,13)(7,16)(7,12)(6,11)(5,9)(4,5)(4,0) (4,0)(0,0) .POL AT (9128,6802) PNTS (0,0)(1,0)(0,113)(4,113)(4,0)(4,0)(0,0) .POL AT (9128,6787) PNTS (7,0)(8,0)(4,2)(2,5)(1,10)(0,15)(4,15)(4,10)(5,6)(6,4)(7,4) (7,4)(7,0) .POL AT (9135,6787) PNTS (503,0)(504,0)(0,0)(0,4)(503,4)(503,4)(503,0) .POL AT (9638,6787) PNTS (8,15)(9,15)(7,10)(5,5)(4,2)(0,0)(0,4)(1,4)(2,6)(4,10)(4,15) (4,15)(8,15) .POL AT (9642,6802) PNTS (4,113)(5,113)(4,0)(0,0)(0,113)(0,113)(4,113) .POL AT (9638,6915) PNTS (0,16)(1,16)(4,13)(5,10)(7,5)(8,0)(4,0)(4,5)(2,9)(1,11)(0,12) (0,12)(0,16) .POL AT (9135,6927) PNTS (0,4)(1,4)(503,4)(503,0)(0,0)(0,0)(0,4) .POL AT (9130,6939) BACKFILL <48 0 0 5 0 0 0> PNTS (5,57)(3,56)(1,55)(1,53)(0,51)(0,5)(1,3)(1,1)(3,0)(5,0)(508,0) (510,0)(512,1)(513,3)(513,5)(513,51)(513,53)(512,55)(510,56) (508,57)(5,57) .POL AT (9128,6990) BACKFILL <1 0 0 5 0 0 0> PNTS (0,0)(1,0)(1,2)(3,5)(5,6)(7,7)(7,3)(6,3)(5,2)(4,2)(4,0)(4,0) (0,0) .POL AT (9128,6944) PNTS (0,0)(1,0)(0,46)(4,46)(4,0)(4,0)(0,0) .POL AT (9128,6936) PNTS (7,0)(8,0)(5,1)(3,3)(1,5)(0,8)(4,8)(4,6)(5,5)(6,4)(7,4)(7,4) (7,0) .POL AT (9135,6936) PNTS (503,0)(504,0)(0,0)(0,4)(503,4)(503,4)(503,0) .POL AT (9638,6936) PNTS (8,8)(9,8)(7,5)(5,3)(3,1)(0,0)(0,4)(2,4)(3,5)(4,6)(4,8)(4,8) (8,8) .POL AT (9642,6944) PNTS (4,46)(5,46)(4,0)(0,0)(0,46)(0,46)(4,46) .POL AT (9638,6990) PNTS (0,7)(1,7)(3,6)(5,5)(7,2)(8,0)(4,0)(4,2)(3,2)(2,3)(0,3)(0,3) (0,7) .POL AT (9135,6994) PNTS (0,6)(1,6)(503,6)(503,0)(0,0)(0,0)(0,6) .POL AT (9297,6788) BACKFILL <2 0 0 5 0 0 0> PNTS (0,0)(0,140)(0,0) .POL AT (9295,6788) BACKFILL <1 0 0 5 0 0 0> PNTS (2,140)(4,140)(4,0)(0,0)(0,140)(2,140)(2,140) .POL AT (9324,6824) BACKFILL <2 0 0 5 0 0 0> PNTS (308,75)(308,0)(0,0)(0,75)(308,75) .POL AT (9631,6823) BACKFILL <1 0 0 5 0 0 0> PNTS (1,3)(0,1)(0,76)(4,76)(4,1)(1,0)(4,1)(4,0)(1,0)(1,3) .POL AT (9322,6823) PNTS (4,1)(2,3)(310,3)(310,0)(2,0)(0,1)(2,0)(0,0)(0,1)(4,1) .POL AT (9322,6824) PNTS (2,74)(4,75)(4,0)(0,0)(0,75)(2,78)(0,75)(0,78)(2,78)(2,74) .POL AT (9324,6898) PNTS (307,1)(308,0)(0,0)(0,4)(308,4)(311,1)(308,4)(311,4)(311,1) (307,1) .POL AT (9289,6780) PNTS (253,8)(253,0)(0,0)(0,8)(253,8) .POL AT (9349,6853) BACKFILL <2 0 0 5 0 0 0> PNTS (0,0)(0,18)(259,18)(259,0)(0,0) .POL AT (9347,6853) BACKFILL <1 0 0 5 0 0 0> PNTS (2,15)(4,18)(4,0)(0,0)(0,18)(2,19)(0,18)(0,19)(2,19)(2,15) .POL AT (9349,6868) PNTS (256,3)(259,0)(0,0)(0,4)(259,4)(260,3)(259,4)(260,4)(260,3) (256,3) .POL AT (9605,6851) PNTS (3,4)(0,2)(0,20)(4,20)(4,2)(3,0)(4,2)(4,0)(3,0)(3,4) .POL AT (9347,6851) PNTS (4,2)(2,4)(261,4)(261,0)(2,0)(0,2)(2,0)(0,0)(0,2)(4,2) .POL AT (9360,6857) BACKFILL <2 0 0 5 0 0 0> PNTS (0,0)(0,10)(236,10)(236,0)(0,0) .POL AT (9358,6857) BACKFILL <1 0 0 5 0 0 0> PNTS (2,7)(4,10)(4,0)(0,0)(0,10)(2,11)(0,10)(0,11)(2,11)(2,7) .POL AT (9360,6864) PNTS (234,3)(236,0)(0,0)(0,4)(236,4)(238,3)(236,4)(238,4)(238,3) (234,3) .POL AT (9594,6855) PNTS (2,4)(0,2)(0,12)(4,12)(4,2)(2,0)(4,2)(4,0)(2,0)(2,4) .POL AT (9358,6855) PNTS (4,2)(2,4)(238,4)(238,0)(2,0)(0,2)(2,0)(0,0)(0,2)(4,2) .POL AT (9552,6637) BACKFILL <52 0 0 5 0 0 0> PNTS (17,27)(17,0)(0,0)(0,27)(17,27) .POL AT (9567,6635) BACKFILL <1 0 0 5 0 0 0> PNTS (2,4)(0,2)(0,29)(4,29)(4,2)(2,0)(4,2)(4,0)(2,0)(2,4) .POL AT (9549,6635) PNTS (4,2)(3,4)(20,4)(20,0)(3,0)(0,2)(3,0)(0,0)(0,2)(4,2) .POL AT (9549,6637) PNTS (3,24)(4,27)(4,0)(0,0)(0,27)(3,28)(0,27)(0,28)(3,28)(3,24) .POL AT (9552,6661) PNTS (15,3)(17,0)(0,0)(0,4)(17,4)(19,3)(17,4)(19,4)(19,3)(15,3) .POL AT (9359,6594) BACKFILL <48 0 0 5 0 0 0> PNTS (24,47)(27,47)(32,46)(36,44)(39,40)(42,37)(45,33)(46,29)(46,24) (46,19)(45,15)(42,11)(39,7)(36,4)(32,2)(27,1)(24,0)(19,1)(14,2) (10,4)(7,7)(4,11)(2,15)(0,19)(0,24)(0,29)(2,33)(4,37)(7,40) (10,44)(14,46)(19,47)(24,47) .POL AT (9383,6618) BACKFILL <1 0 0 5 0 0 0> PNTS (21,0)(22,0)(21,5)(19,8)(18,12)(15,16)(11,19)(7,20)(3,22)(0,22) (0,25)(3,24)(8,23)(13,21)(16,17)(20,14)(22,9)(23,5)(24,0)(24,0) (21,0) .POL AT (9383,6592) PNTS (0,4)(1,4)(3,4)(7,5)(11,8)(15,10)(18,14)(19,17)(21,21)(21,26) (24,26)(23,21)(22,16)(20,12)(16,8)(13,5)(8,3)(3,1)(0,0)(0,0) (0,4) .POL AT (9357,6592) PNTS (4,26)(5,26)(4,21)(5,17)(7,14)(10,10)(13,8)(17,5)(21,4)(26,4) (26,0)(21,1)(16,3)(11,5)(8,8)(4,12)(3,16)(1,21)(0,26)(0,26) (4,26) .POL AT (9357,6618) PNTS (26,22)(27,22)(21,22)(17,20)(13,19)(10,16)(7,12)(5,8)(4,5) (4,0)(0,0)(1,5)(3,9)(4,14)(8,17)(11,21)(16,23)(21,24)(26,25) (26,25)(26,22) .POL AT (9472,6594) BACKFILL <48 0 0 5 0 0 0> PNTS (24,47)(28,47)(33,46)(37,44)(40,40)(43,37)(45,33)(46,29)(47,24) (46,19)(45,15)(43,11)(40,7)(37,4)(33,2)(28,1)(24,0)(19,1)(15,2) (11,4)(7,7)(4,11)(2,15)(1,19)(0,24)(1,29)(2,33)(4,37)(7,40) (11,44)(15,46)(19,47)(24,47) .POL AT (9496,6618) BACKFILL <1 0 0 5 0 0 0> PNTS (22,0)(23,0)(22,5)(20,8)(18,12)(15,16)(12,19)(8,20)(4,22)(0,22) (0,25)(4,24)(9,23)(14,21)(17,17)(20,14)(22,9)(24,5)(25,0)(25,0) (22,0) .POL AT (9496,6592) PNTS (0,4)(1,4)(4,4)(8,5)(12,8)(15,10)(18,14)(20,17)(22,21)(22,26) (25,26)(24,21)(22,16)(20,12)(17,8)(14,5)(9,3)(4,1)(0,0)(0,0) (0,4) .POL AT (9470,6592) PNTS (3,26)(4,26)(3,21)(5,17)(7,14)(10,10)(14,8)(17,5)(21,4)(26,4) (26,0)(21,1)(16,3)(12,5)(8,8)(5,12)(3,16)(1,21)(0,26)(0,26) (3,26) .POL AT (9470,6618) BACKFILL <48 0 0 5 0 0 0> PNTS (26,22)(27,22)(21,22)(17,20)(14,19)(10,16)(7,12)(5,8)(3,5) (3,0)(0,0)(1,5)(3,9)(5,14)(8,17)(12,21)(16,23)(21,24)(26,25) (26,25)(26,22) .POL AT (9297,6594) PNTS (24,47)(29,47)(34,46)(37,44)(41,40)(44,37)(46,33)(48,29)(48,24) (48,19)(46,15)(44,11)(41,7)(37,4)(34,2)(29,1)(24,0)(19,1)(15,2) (11,4)(7,7)(4,11)(3,15)(1,19)(0,24)(1,29)(3,33)(4,37)(7,40) (11,44)(15,46)(19,47)(24,47) .POL AT (9321,6618) BACKFILL <1 0 0 5 0 0 0> PNTS (22,0)(23,0)(22,5)(21,8)(19,12)(16,16)(13,19)(9,20)(5,22)(0,22) (0,25)(5,24)(10,23)(14,21)(17,17)(21,14)(23,9)(25,5)(25,0) (25,0)(22,0) .POL AT (9321,6592) PNTS (0,4)(1,4)(5,4)(9,5)(13,8)(16,10)(19,14)(21,17)(22,21)(22,26) (25,26)(25,21)(23,16)(21,12)(17,8)(14,5)(10,3)(5,1)(0,0)(0,0) (0,4) .POL AT (9296,6592) PNTS (3,26)(4,26)(3,21)(4,17)(7,14)(9,10)(13,8)(16,5)(20,4)(25,4) (25,0)(20,1)(16,3)(12,5)(8,8)(4,12)(2,16)(1,21)(0,26)(0,26) (3,26) .POL AT (9296,6618) PNTS (25,22)(26,22)(20,22)(16,20)(13,19)(9,16)(7,12)(4,8)(3,5)(3,0) (0,0)(1,5)(2,9)(4,14)(8,17)(12,21)(16,23)(20,24)(25,25)(25,25) (25,22) .POL AT (9236,6594) BACKFILL <48 0 0 5 0 0 0> PNTS (23,47)(28,47)(33,46)(37,44)(40,40)(43,37)(46,33)(47,29)(47,24) (47,19)(46,15)(43,11)(40,7)(37,4)(33,2)(28,1)(23,0)(19,1)(15,2) (11,4)(7,7)(4,11)(2,15)(0,19)(0,24)(0,29)(2,33)(4,37)(7,40) (11,44)(15,46)(19,47)(23,47) .POL AT (9259,6618) BACKFILL <1 0 0 5 0 0 0> PNTS (23,0)(24,0)(23,5)(21,8)(19,12)(16,16)(13,19)(9,20)(5,22)(0,22) (0,25)(5,24)(10,23)(15,21)(18,17)(22,14)(23,9)(25,5)(26,0) (26,0)(23,0) .POL AT (9259,6592) PNTS (0,4)(1,4)(5,4)(9,5)(13,8)(16,10)(19,14)(21,17)(23,21)(23,26) (26,26)(25,21)(23,16)(22,12)(18,8)(15,5)(10,3)(5,1)(0,0)(0,0) (0,4) .POL AT (9234,6592) PNTS (3,26)(4,26)(3,21)(5,17)(7,14)(10,10)(14,8)(17,5)(21,4)(25,4) (25,0)(21,1)(16,3)(12,5)(8,8)(5,12)(2,16)(1,21)(0,26)(0,26) (3,26) .POL AT (9234,6618) PNTS (25,22)(26,22)(21,22)(17,20)(14,19)(10,16)(7,12)(5,8)(3,5) (3,0)(0,0)(1,5)(2,9)(5,14)(8,17)(12,21)(16,23)(21,24)(25,25) (25,25)(25,22) .POL AT (9000,6002) BACKFILL <48 0 0 5 0 0 0> PNTS (21,0)(18,0)(14,2)(10,3)(6,6)(3,9)(2,12)(0,15)(0,19)(0,603) (0,607)(2,610)(3,613)(6,617)(10,619)(14,621)(18,622)(21,622) (752,622)(756,622)(760,621)(764,619)(767,617)(770,613)(771,610) (773,607)(773,603)(773,19)(773,15)(771,12)(770,9)(767,6)(764,3) (760,2)(756,0)(752,0)(21,0) .POL AT (8998,6000) BACKFILL <1 0 0 5 0 0 0> PNTS (4,21)(5,21)(4,18)(5,15)(7,12)(9,8)(12,7)(16,5)(20,4)(23,4) (23,0)(20,1)(15,2)(11,4)(7,6)(4,10)(2,13)(1,17)(0,21)(0,21) (4,21) .POL AT (8998,6021) PNTS (4,584)(5,584)(4,0)(0,0)(0,584)(0,584)(4,584) .POL AT (8998,6605) PNTS (23,18)(24,18)(20,18)(16,16)(12,14)(9,13)(7,10)(5,6)(4,3)(4,0) (0,0)(1,4)(2,8)(4,11)(7,15)(11,18)(15,19)(20,21)(23,21)(23,21) (23,18) .POL AT (9021,6623) PNTS (731,0)(732,0)(0,0)(0,3)(731,3)(731,3)(731,0) .POL AT (9752,6605) PNTS (19,0)(20,0)(19,3)(18,6)(16,10)(14,13)(12,14)(8,16)(4,18)(0,18) (0,21)(4,21)(9,19)(13,18)(16,15)(19,11)(21,8)(23,4)(23,0)(23,0) (19,0) .POL AT (9771,6021) PNTS (0,0)(1,0)(0,584)(4,584)(4,0)(4,0)(0,0) .POL AT (9752,6000) PNTS (0,4)(1,4)(4,4)(8,5)(12,7)(14,8)(16,12)(18,15)(19,18)(19,21) (23,21)(23,17)(21,13)(19,10)(16,6)(13,4)(9,2)(4,1)(0,0)(0,0) (0,4) .POL AT (9021,6000) PNTS (0,4)(1,4)(731,4)(731,0)(0,0)(0,0)(0,4) .POL AT (9093,6076) PNTS (4,17)(5,17)(4,15)(4,12)(6,10)(8,8)(10,6)(12,5)(15,4)(18,4) (18,0)(15,1)(11,2)(8,3)(5,5)(4,8)(1,11)(0,14)(0,17)(0,17)(4,17) .POL AT (9093,6093) PNTS (4,440)(5,440)(4,0)(0,0)(0,440)(0,440)(4,440) .POL AT (9093,6533) PNTS (18,13)(19,13)(15,13)(12,12)(10,11)(8,10)(6,7)(4,5)(4,3)(4,0) (0,0)(0,3)(1,7)(4,9)(5,12)(8,14)(11,15)(15,16)(18,17)(18,17) (18,13) .POL AT (9111,6546) PNTS (551,0)(552,0)(0,0)(0,4)(551,4)(551,4)(551,0) .POL AT (9662,6533) PNTS (15,0)(16,0)(15,3)(14,5)(13,7)(11,10)(9,11)(7,12)(4,13)(0,13) (0,17)(4,16)(7,15)(11,14)(13,12)(15,9)(17,7)(18,3)(19,0)(19,0) (15,0) .POL AT (9677,6093) PNTS (0,0)(1,0)(0,440)(4,440)(4,0)(4,0)(0,0) .POL AT (9662,6076) PNTS (0,4)(1,4)(4,4)(7,5)(9,6)(11,8)(13,10)(14,12)(15,15)(15,17) (19,17)(18,14)(17,11)(15,8)(13,5)(11,3)(7,2)(4,1)(0,0)(0,0) (0,4) .POL AT (9111,6076) PNTS (0,4)(1,4)(551,4)(551,0)(0,0)(0,0)(0,4) .POL AT (9110,6091) BACKFILL <53 0 0 5 0 0 0> PNTS (16,0)(13,0)(9,0)(7,2)(5,4)(3,6)(2,8)(1,11)(0,13)(0,431)(1,433) (2,436)(3,438)(5,441)(7,442)(9,444)(13,445)(16,445)(538,445) (541,445)(544,444)(547,442)(549,441)(551,438)(552,436)(553,433) (553,431)(553,13)(553,11)(552,8)(551,6)(549,4)(547,2)(544,0) (541,0)(538,0)(16,0) .POL AT (9108,6088) BACKFILL <1 0 0 5 0 0 0> PNTS (4,16)(5,16)(4,14)(5,12)(7,10)(8,7)(10,7)(12,5)(15,4)(18,4) (18,0)(15,1)(11,2)(8,3)(5,5)(4,8)(2,11)(1,13)(0,16)(0,16)(4,16) .POL AT (9108,6104) PNTS (4,418)(5,418)(4,0)(0,0)(0,418)(0,418)(4,418) .POL AT (9108,6522) PNTS (18,12)(19,12)(15,12)(12,11)(10,10)(8,9)(7,6)(5,4)(4,2)(4,0) (0,0)(1,3)(2,6)(4,8)(5,11)(8,13)(11,14)(15,15)(18,16)(18,16) (18,12) .POL AT (9126,6534) PNTS (522,0)(523,0)(0,0)(0,4)(522,4)(522,4)(522,0) .POL AT (9648,6522) PNTS (14,0)(15,0)(14,2)(13,4)(11,6)(10,9)(8,10)(6,11)(3,12)(0,12) (0,16)(3,15)(6,14)(10,13)(12,11)(14,8)(16,6)(17,3)(18,0)(18,0) (14,0) .POL AT (9662,6104) PNTS (0,0)(1,0)(0,418)(4,418)(4,0)(4,0)(0,0) .POL AT (9648,6088) PNTS (0,4)(1,4)(3,4)(6,5)(8,7)(10,7)(11,10)(13,12)(14,14)(14,16) (18,16)(17,13)(16,11)(14,8)(12,5)(10,3)(6,2)(3,1)(0,0)(0,0) (0,4) .POL AT (9126,6088) PNTS (0,4)(1,4)(522,4)(522,0)(0,0)(0,0)(0,4) END .GRP END PICTURE NOTES .GRP BACKFILL <34 2 5 1000 0 0 0> LINEFILL <21 21 5 1000 0 0 0> SHADOW <11 0 15 15> THICKNESS 1 FONT 2 .TMP AT (250,250) RECOLOR ON TEMPLATE_FLAGS <5 14 0 0> T_POS <250 250 7249 4875> .VOID .TMP AT (250,5125) RECOLOR ON TEMPLATE_FLAGS <6 15 0 0> T_POS <250 5125 7249 9749> .VOID END .GRP END NOTES SLIDE_INFO SLIDE_STYLE <0 -1 1> LAYOUT_ID <1 2 12 12 12> END SLIDE_INFO PICTURE .RECT AT (3500,5685) RECOLOR ON BACKFILL <34 2 0 0 0 0 0> PARA <0 0 0 0 1000 34 0 111> PNTS (0,0)(2500,0)(2500,639)(0,639)(0,0) .TMP AT (105,85) RECOLOR ON TEMPLATE_FLAGS <1 0 0 0> T_POS <105 85 9892 1504> .TXT AT (506,212) RECOLOR ON TEMPLATED ON BACKFILL <7 7 0 0 0 0 0> PARA <0 0 0 0 1000 1 0 111> V_SPACE <0 611 0> SIZE 440000 BOLD ON HOR_JUST CENTER L_SPACE 611 MARGINS <0 0 0 0> TXTXYOFF <-4 437> T_PNTS (-1,433)(-1,-4)(8921,-4)(8921,443)(-1,443)(-1,433)(8921,433) H_SPACE 9788 .STR "The \"man in the middle\" attack" .TMP AT (105,1562) RECOLOR ON TEMPLATE_FLAGS <2 3 0 0> T_POS <105 1562 9892 7370> .TXT AT (28,1623) RECOLOR ON TEMPLATED ON BACKFILL <20 20 0 0 0 0 0> PARA <-500 500 -500 1 1000 0 3 108> V_SPACE <333 444 0> SIZE 320000 BOLD OFF HOR_JUST LEFT L_SPACE 444 TXTXYOFF <13 317> T_PNTS (-5,315)(-5,-2)(9263,-2)(9263,3299)(-5,3299)(-5,315)(9263,315) .STR "However, someone who is able to actively intercept and modify y our traffic can pretend to be the other side" .STR "\nThe attacker can negotiate separate encryption keys with both sides" .STR "\nYou think your traffic is secure, but it isn't!" .LINE AT (1000,6001) RECOLOR ON BACKFILL <34 2 5 1000 0 0 0> THICKNESS 56 R_ARROW 1 PARA <0 0 0 0 1000 34 0 111> V_SPACE <0 250 0> SIZE 180000 L_SPACE 250 MARGINS <125 125 250 62> PNTS (0,0)(7750,0) .GRP THICKNESS 1 R_ARROW 0 PARA <0 0 0 0 1000 1 0 111> .ELL AT (1250,5751) RECOLOR ON BACKFILL <7 2 5 1000 0 0 0> PARA <0 0 0 0 1000 34 0 111> PNTS (0,0)(500,0)(500,500)(0,500)(0,0) .LINE AT (1330,5824) RECOLOR ON BACKFILL <34 2 5 1000 0 0 0> LINEFILL <1 21 5 1000 0 0 0> THICKNESS 42 PNTS (0,354)(347,0) .LINE AT (1337,5837) RECOLOR ON PNTS (0,0)(340,341) END .GRP .GRP LINEFILL <21 21 5 1000 0 0 0> THICKNESS 1 PARA <0 0 0 0 1000 1 0 111> .ELL AT (3751,5753) RECOLOR ON BACKFILL <7 2 5 1000 0 0 0> PARA <0 0 0 0 1000 34 0 111> PNTS (0,0)(500,0)(500,500)(0,500)(0,0) .LINE AT (3831,5826) RECOLOR ON BACKFILL <34 2 5 1000 0 0 0> LINEFILL <1 21 5 1000 0 0 0> THICKNESS 42 PNTS (0,354)(347,0) .LINE AT (3838,5839) RECOLOR ON PNTS (0,0)(340,341) END .GRP .GRP LINEFILL <21 21 5 1000 0 0 0> THICKNESS 1 PARA <0 0 0 0 1000 1 0 111> .ELL AT (7751,5752) RECOLOR ON BACKFILL <27 2 5 1000 0 0 0> PARA <0 0 0 0 1000 34 0 111> PNTS (0,0)(500,0)(500,500)(0,500)(0,0) .LINE AT (7831,5825) RECOLOR ON BACKFILL <34 2 5 1000 0 0 0> LINEFILL <1 21 5 1000 0 0 0> THICKNESS 42 PNTS (0,354)(347,0) .LINE AT (7838,5838) RECOLOR ON PNTS (0,0)(340,341) END .GRP .GRP LINEFILL <21 21 5 1000 0 0 0> THICKNESS 1 PARA <0 0 0 0 1000 1 0 111> .ELL AT (5248,5753) RECOLOR ON BACKFILL <27 2 5 1000 0 0 0> PARA <0 0 0 0 1000 34 0 111> PNTS (0,0)(500,0)(500,500)(0,500)(0,0) .LINE AT (5328,5826) RECOLOR ON BACKFILL <34 2 5 1000 0 0 0> LINEFILL <1 21 5 1000 0 0 0> THICKNESS 42 PNTS (0,354)(347,0) .LINE AT (5335,5839) RECOLOR ON PNTS (0,0)(340,341) END .GRP .POL AT (1500,5500) RECOLOR ON LINEFILL <21 21 5 1000 0 0 0> THICKNESS 1 L_ARROW 1 R_ARROW 1 PNTS (0,0)(2500,0) .TXT AT (2356,5504) RECOLOR ON BACKFILL <20 20 5 1000 0 0 0> THICKNESS 0 L_ARROW 0 R_ARROW 0 MARGINS <0 0 0 0> TXTXYOFF <-16 178> T_PNTS (0,178)(0,0)(529,0)(529,233)(0,233)(0,178)(529,178) H_SPACE 0 .STR "key 1" .POL AT (5500,5500) RECOLOR ON BACKFILL <34 2 5 1000 0 0 0> THICKNESS 1 L_ARROW 1 R_ARROW 1 MARGINS <125 125 250 62> PNTS (0,0)(2500,0) .TXT AT (6351,5500) RECOLOR ON BACKFILL <20 20 5 1000 0 0 0> THICKNESS 0 L_ARROW 0 R_ARROW 0 MARGINS <0 0 0 0> T_PNTS (0,178)(0,0)(569,0)(569,233)(0,233)(0,178)(569,178) .STR "key 2" .LINE AT (4750,6186) RECOLOR ON BACKFILL <34 2 5 1000 0 0 0> THICKNESS 56 R_ARROW 1 MARGINS <125 125 250 62> PNTS (0,0)(0,500) .TXT AT (2134,6732) RECOLOR ON BACKFILL <20 20 5 1000 0 0 0> THICKNESS 0 R_ARROW 0 V_SPACE <0 333 0> SIZE 240000 HOR_JUST CENTER L_SPACE 333 MARGINS <0 0 0 0> TXTXYOFF <3 241> T_PNTS (0,241)(0,0)(5114,0)(5114,649)(0,649)(0,241)(5114,241) .STR L_SPACE 250 "Attacker sees all traffic in plain text\n- and can modify it!" .ELL AT (315,5318) RECOLOR ON BACKFILL <34 2 0 0 0 0 0> THICKNESS 1 V_SPACE <0 250 0> SIZE 180000 HOR_JUST LEFT MARGINS <125 125 250 62> PNTS (0,0)(377,0)(377,432)(0,432)(0,0) .LINE AT (500,5750) RECOLOR ON BACKFILL <34 2 5 1000 0 0 0> PNTS (0,0)(0,500) .LINE AT (250,6250) RECOLOR ON PNTS (250,0)(0,250) .LINE AT (500,6250) RECOLOR ON PNTS (0,0)(250,250) .LINE AT (250,6000) RECOLOR ON PNTS (0,0)(500,0) .GRP BACKFILL <1 0 0 0 0 0 0> LINEFILL <1 2 5 1000 0 0 0> SHADOW <6 0 15 15> PARA <0 0 0 0 1000 1 0 111> FONT 0 .POL AT (9104,6273) BACKFILL <48 0 0 5 0 0 0> THICKNESS 0 PNTS (512,185)(512,0)(0,0)(0,185)(512,185) .POL AT (9606,6271) BACKFILL <1 0 0 5 0 0 0> PNTS (2,4)(0,2)(0,187)(4,187)(4,2)(2,0)(4,2)(4,0)(2,0)(2,4) .POL AT (9114,6271) PNTS (4,2)(3,4)(494,4)(494,0)(3,0)(0,2)(3,0)(0,0)(0,2)(4,2) .POL AT (9114,6273) PNTS (3,183)(4,185)(4,0)(0,0)(0,185)(3,187)(0,185)(0,187)(3,187) (3,183) .POL AT (9117,6456) BACKFILL <49 0 0 5 0 0 0> PNTS (489,2)(491,0)(0,0)(0,4)(491,4)(493,2)(491,4)(493,4)(493,2) (489,2) .POL AT (9106,6125) BACKFILL <48 0 0 5 0 0 0> PNTS (0,0)(7,50)(507,50)(513,0)(0,0) .POL AT (9104,6125) BACKFILL <1 0 0 5 0 0 0> PNTS (9,49)(10,50)(3,0)(0,0)(7,50)(9,53)(7,50)(7,53)(9,53)(9,49) .POL AT (9113,6174) PNTS (498,1)(500,0)(0,0)(0,4)(500,4)(502,1)(500,4)(502,4)(502,1) (498,1) .POL AT (9611,6123) PNTS (8,3)(7,2)(0,52)(4,52)(10,2)(8,0)(10,2)(11,0)(8,0)(8,3) .POL AT (9104,6123) PNTS (3,2)(2,3)(515,3)(515,0)(2,0)(0,2)(2,0)(0,0)(0,2)(3,2) .POL AT (9572,6134) PNTS (2,4)(0,1)(0,31)(4,31)(4,1)(2,0)(4,1)(4,0)(2,0)(2,4) .POL AT (9514,6134) PNTS (4,1)(3,4)(60,4)(60,0)(3,0)(0,1)(3,0)(0,0)(0,1)(4,1) .POL AT (9514,6135) PNTS (3,28)(4,30)(4,0)(0,0)(0,30)(3,32)(0,30)(0,32)(3,32)(3,28) .POL AT (9517,6163) PNTS (55,2)(57,0)(0,0)(0,4)(57,4)(59,2)(57,4)(59,4)(59,2)(55,2) .POL AT (9517,6137) BACKFILL <50 0 0 5 0 0 0> PNTS (19,27)(19,0)(0,0)(0,27)(19,27) .POL AT (9533,6135) BACKFILL <1 0 0 5 0 0 0> PNTS (3,4)(0,2)(0,29)(4,29)(4,2)(3,0)(4,2)(4,0)(3,0)(3,4) .POL AT (9516,6135) PNTS (4,2)(1,4)(20,4)(20,0)(1,0)(0,2)(1,0)(0,0)(0,2)(4,2) .POL AT (9516,6137) PNTS (1,24)(4,27)(4,0)(0,0)(0,27)(1,28)(0,27)(0,28)(1,28)(1,24) .POL AT (9517,6161) PNTS (16,3)(19,0)(0,0)(0,4)(19,4)(20,3)(19,4)(20,4)(20,3)(16,3) .POL AT (9213,6175) BACKFILL <51 0 0 5 0 0 0> PNTS (45,24)(0,0)(299,0)(254,24)(45,24) .POL AT (9206,6174) BACKFILL <1 0 0 5 0 0 0> PNTS (7,0)(6,3)(52,27)(53,24)(8,0)(7,4)(7,0)(0,0)(6,3)(7,0) .POL AT (9213,6174) PNTS (300,3)(299,0)(0,0)(0,4)(299,4)(298,0)(300,3)(307,0)(299,0) (300,3) .POL AT (9466,6174) PNTS (1,28)(2,27)(47,3)(45,0)(0,24)(1,24)(1,28)(2,28)(2,27)(1,28) .POL AT (9258,6198) PNTS (0,3)(0,4)(209,4)(209,0)(0,0)(1,0)(0,3)(0,4)(0,4)(0,3) .POL AT (9245,6199) BACKFILL <48 0 0 5 0 0 0> PNTS (13,0)(0,25)(236,25)(222,0)(13,0) .POL AT (9242,6198) BACKFILL <1 0 0 5 0 0 0> PNTS (3,23)(4,26)(18,2)(15,0)(1,25)(3,27)(1,25)(0,27)(3,27)(3,23) .POL AT (9245,6221) PNTS (234,3)(236,0)(0,0)(0,4)(236,4)(238,2)(236,4)(239,4)(238,2) (234,3) .POL AT (9465,6198) PNTS (2,4)(0,2)(14,26)(18,25)(3,0)(2,0)(3,0)(3,0)(2,0)(2,4) .POL AT (9257,6198) PNTS (3,2)(1,4)(210,4)(210,0)(1,0)(0,0)(1,0)(1,0)(0,0)(3,2) .POL AT (9025,6123) PNTS (32,24)(39,0)(0,0)(6,24)(32,24) .POL AT (9055,6121) PNTS (9,4)(7,2)(0,26)(3,27)(10,2)(9,0)(10,2)(11,0)(9,0)(9,4) .POL AT (9023,6121) PNTS (4,2)(2,4)(41,4)(41,0)(2,0)(1,2)(2,0)(0,0)(1,2)(4,2) .POL AT (9024,6123) PNTS (7,22)(9,24)(3,0)(0,0)(6,25)(7,26)(6,25)(7,26)(7,26)(7,22) .POL AT (9031,6145) PNTS (24,2)(26,0)(0,0)(0,4)(26,4)(27,3)(26,4)(27,4)(27,3)(24,2) .POL AT (9662,6123) BACKFILL <49 0 0 5 0 0 0> PNTS (6,24)(0,0)(39,0)(32,24)(6,24) .POL AT (9660,6121) BACKFILL <1 0 0 5 0 0 0> PNTS (2,0)(0,2)(7,27)(10,26)(4,2)(2,4)(2,0)(0,0)(0,2)(2,0) .POL AT (9662,6121) PNTS (40,2)(39,0)(0,0)(0,4)(39,4)(37,2)(40,2)(41,0)(39,0)(40,2) .POL AT (9693,6123) PNTS (1,26)(3,25)(9,0)(6,0)(0,24)(1,22)(1,26)(2,26)(3,25)(1,26) .POL AT (9667,6145) PNTS (0,3)(1,4)(27,4)(27,0)(1,0)(3,2)(0,3)(1,4)(1,4)(0,3) .POL AT (9106,6224) BACKFILL <48 0 0 5 0 0 0> PNTS (5,57)(3,56)(1,55)(1,53)(0,51)(0,5)(1,3)(1,1)(3,0)(5,0)(508,0) (510,0)(512,1)(513,3)(513,5)(513,51)(513,53)(512,55)(510,56) (508,57)(5,57) .POL AT (9104,6275) BACKFILL <1 0 0 5 0 0 0> PNTS (0,0)(1,0)(1,2)(3,5)(5,6)(7,7)(7,3)(6,3)(5,2)(4,2)(4,0)(4,0) (0,0) .POL AT (9104,6229) PNTS (0,0)(1,0)(0,46)(4,46)(4,0)(4,0)(0,0) .POL AT (9104,6221) PNTS (7,0)(8,0)(5,1)(3,3)(1,5)(0,8)(4,8)(4,6)(5,5)(6,4)(7,4)(7,4) (7,0) .POL AT (9111,6221) PNTS (503,0)(504,0)(0,0)(0,4)(503,4)(503,4)(503,0) .POL AT (9614,6221) PNTS (8,8)(9,8)(7,5)(5,3)(3,1)(0,0)(0,4)(2,4)(3,5)(4,6)(4,8)(4,8) (8,8) .POL AT (9618,6229) PNTS (4,46)(5,46)(4,0)(0,0)(0,46)(0,46)(4,46) .POL AT (9614,6275) PNTS (0,7)(1,7)(3,6)(5,5)(7,2)(8,0)(4,0)(4,2)(3,2)(2,3)(0,3)(0,3) (0,7) .POL AT (9111,6278) PNTS (0,4)(1,4)(503,4)(503,0)(0,0)(0,0)(0,4) .POL AT (9104,6415) PNTS (0,0)(1,0)(1,5)(2,10)(4,13)(7,16)(7,12)(6,11)(5,9)(4,5)(4,0) (4,0)(0,0) .POL AT (9104,6302) PNTS (0,0)(1,0)(0,113)(4,113)(4,0)(4,0)(0,0) .POL AT (9104,6287) PNTS (7,0)(8,0)(4,2)(2,5)(1,10)(0,15)(4,15)(4,10)(5,6)(6,4)(7,4) (7,4)(7,0) .POL AT (9111,6287) PNTS (503,0)(504,0)(0,0)(0,4)(503,4)(503,4)(503,0) .POL AT (9614,6287) PNTS (8,15)(9,15)(7,10)(5,5)(4,2)(0,0)(0,4)(1,4)(2,6)(4,10)(4,15) (4,15)(8,15) .POL AT (9618,6302) PNTS (4,113)(5,113)(4,0)(0,0)(0,113)(0,113)(4,113) .POL AT (9614,6415) PNTS (0,16)(1,16)(4,13)(5,10)(7,5)(8,0)(4,0)(4,5)(2,9)(1,11)(0,12) (0,12)(0,16) .POL AT (9111,6427) PNTS (0,4)(1,4)(503,4)(503,0)(0,0)(0,0)(0,4) .POL AT (9106,6439) BACKFILL <48 0 0 5 0 0 0> PNTS (5,57)(3,56)(1,55)(1,53)(0,51)(0,5)(1,3)(1,1)(3,0)(5,0)(508,0) (510,0)(512,1)(513,3)(513,5)(513,51)(513,53)(512,55)(510,56) (508,57)(5,57) .POL AT (9104,6490) BACKFILL <1 0 0 5 0 0 0> PNTS (0,0)(1,0)(1,2)(3,5)(5,6)(7,7)(7,3)(6,3)(5,2)(4,2)(4,0)(4,0) (0,0) .POL AT (9104,6444) PNTS (0,0)(1,0)(0,46)(4,46)(4,0)(4,0)(0,0) .POL AT (9104,6436) PNTS (7,0)(8,0)(5,1)(3,3)(1,5)(0,8)(4,8)(4,6)(5,5)(6,4)(7,4)(7,4) (7,0) .POL AT (9111,6436) PNTS (503,0)(504,0)(0,0)(0,4)(503,4)(503,4)(503,0) .POL AT (9614,6436) PNTS (8,8)(9,8)(7,5)(5,3)(3,1)(0,0)(0,4)(2,4)(3,5)(4,6)(4,8)(4,8) (8,8) .POL AT (9618,6444) PNTS (4,46)(5,46)(4,0)(0,0)(0,46)(0,46)(4,46) .POL AT (9614,6490) PNTS (0,7)(1,7)(3,6)(5,5)(7,2)(8,0)(4,0)(4,2)(3,2)(2,3)(0,3)(0,3) (0,7) .POL AT (9111,6494) PNTS (0,6)(1,6)(503,6)(503,0)(0,0)(0,0)(0,6) .POL AT (9273,6288) BACKFILL <2 0 0 5 0 0 0> PNTS (0,0)(0,140)(0,0) .POL AT (9271,6288) BACKFILL <1 0 0 5 0 0 0> PNTS (2,140)(4,140)(4,0)(0,0)(0,140)(2,140)(2,140) .POL AT (9300,6324) BACKFILL <2 0 0 5 0 0 0> PNTS (308,75)(308,0)(0,0)(0,75)(308,75) .POL AT (9607,6323) BACKFILL <1 0 0 5 0 0 0> PNTS (1,3)(0,1)(0,76)(4,76)(4,1)(1,0)(4,1)(4,0)(1,0)(1,3) .POL AT (9298,6323) PNTS (4,1)(2,3)(310,3)(310,0)(2,0)(0,1)(2,0)(0,0)(0,1)(4,1) .POL AT (9298,6324) PNTS (2,74)(4,75)(4,0)(0,0)(0,75)(2,78)(0,75)(0,78)(2,78)(2,74) .POL AT (9300,6398) PNTS (307,1)(308,0)(0,0)(0,4)(308,4)(311,1)(308,4)(311,4)(311,1) (307,1) .POL AT (9265,6280) PNTS (253,8)(253,0)(0,0)(0,8)(253,8) .POL AT (9325,6353) BACKFILL <2 0 0 5 0 0 0> PNTS (0,0)(0,18)(259,18)(259,0)(0,0) .POL AT (9323,6353) BACKFILL <1 0 0 5 0 0 0> PNTS (2,15)(4,18)(4,0)(0,0)(0,18)(2,19)(0,18)(0,19)(2,19)(2,15) .POL AT (9325,6368) PNTS (256,3)(259,0)(0,0)(0,4)(259,4)(260,3)(259,4)(260,4)(260,3) (256,3) .POL AT (9581,6351) PNTS (3,4)(0,2)(0,20)(4,20)(4,2)(3,0)(4,2)(4,0)(3,0)(3,4) .POL AT (9323,6351) PNTS (4,2)(2,4)(261,4)(261,0)(2,0)(0,2)(2,0)(0,0)(0,2)(4,2) .POL AT (9336,6357) BACKFILL <2 0 0 5 0 0 0> PNTS (0,0)(0,10)(236,10)(236,0)(0,0) .POL AT (9334,6357) BACKFILL <1 0 0 5 0 0 0> PNTS (2,7)(4,10)(4,0)(0,0)(0,10)(2,11)(0,10)(0,11)(2,11)(2,7) .POL AT (9336,6364) PNTS (234,3)(236,0)(0,0)(0,4)(236,4)(238,3)(236,4)(238,4)(238,3) (234,3) .POL AT (9570,6355) PNTS (2,4)(0,2)(0,12)(4,12)(4,2)(2,0)(4,2)(4,0)(2,0)(2,4) .POL AT (9334,6355) PNTS (4,2)(2,4)(238,4)(238,0)(2,0)(0,2)(2,0)(0,0)(0,2)(4,2) .POL AT (9528,6137) BACKFILL <52 0 0 5 0 0 0> PNTS (17,27)(17,0)(0,0)(0,27)(17,27) .POL AT (9543,6135) BACKFILL <1 0 0 5 0 0 0> PNTS (2,4)(0,2)(0,29)(4,29)(4,2)(2,0)(4,2)(4,0)(2,0)(2,4) .POL AT (9525,6135) PNTS (4,2)(3,4)(20,4)(20,0)(3,0)(0,2)(3,0)(0,0)(0,2)(4,2) .POL AT (9525,6137) PNTS (3,24)(4,27)(4,0)(0,0)(0,27)(3,28)(0,27)(0,28)(3,28)(3,24) .POL AT (9528,6161) PNTS (15,3)(17,0)(0,0)(0,4)(17,4)(19,3)(17,4)(19,4)(19,3)(15,3) .POL AT (9335,6094) BACKFILL <48 0 0 5 0 0 0> PNTS (24,47)(27,47)(32,46)(36,44)(39,40)(42,37)(45,33)(46,29)(46,24) (46,19)(45,15)(42,11)(39,7)(36,4)(32,2)(27,1)(24,0)(19,1)(14,2) (10,4)(7,7)(4,11)(2,15)(0,19)(0,24)(0,29)(2,33)(4,37)(7,40) (10,44)(14,46)(19,47)(24,47) .POL AT (9359,6118) BACKFILL <1 0 0 5 0 0 0> PNTS (21,0)(22,0)(21,5)(19,8)(18,12)(15,16)(11,19)(7,20)(3,22)(0,22) (0,25)(3,24)(8,23)(13,21)(16,17)(20,14)(22,9)(23,5)(24,0)(24,0) (21,0) .POL AT (9359,6092) PNTS (0,4)(1,4)(3,4)(7,5)(11,8)(15,10)(18,14)(19,17)(21,21)(21,26) (24,26)(23,21)(22,16)(20,12)(16,8)(13,5)(8,3)(3,1)(0,0)(0,0) (0,4) .POL AT (9333,6092) PNTS (4,26)(5,26)(4,21)(5,17)(7,14)(10,10)(13,8)(17,5)(21,4)(26,4) (26,0)(21,1)(16,3)(11,5)(8,8)(4,12)(3,16)(1,21)(0,26)(0,26) (4,26) .POL AT (9333,6118) PNTS (26,22)(27,22)(21,22)(17,20)(13,19)(10,16)(7,12)(5,8)(4,5) (4,0)(0,0)(1,5)(3,9)(4,14)(8,17)(11,21)(16,23)(21,24)(26,25) (26,25)(26,22) .POL AT (9448,6094) BACKFILL <48 0 0 5 0 0 0> PNTS (24,47)(28,47)(33,46)(37,44)(40,40)(43,37)(45,33)(46,29)(47,24) (46,19)(45,15)(43,11)(40,7)(37,4)(33,2)(28,1)(24,0)(19,1)(15,2) (11,4)(7,7)(4,11)(2,15)(1,19)(0,24)(1,29)(2,33)(4,37)(7,40) (11,44)(15,46)(19,47)(24,47) .POL AT (9472,6118) BACKFILL <1 0 0 5 0 0 0> PNTS (22,0)(23,0)(22,5)(20,8)(18,12)(15,16)(12,19)(8,20)(4,22)(0,22) (0,25)(4,24)(9,23)(14,21)(17,17)(20,14)(22,9)(24,5)(25,0)(25,0) (22,0) .POL AT (9472,6092) PNTS (0,4)(1,4)(4,4)(8,5)(12,8)(15,10)(18,14)(20,17)(22,21)(22,26) (25,26)(24,21)(22,16)(20,12)(17,8)(14,5)(9,3)(4,1)(0,0)(0,0) (0,4) .POL AT (9446,6092) PNTS (3,26)(4,26)(3,21)(5,17)(7,14)(10,10)(14,8)(17,5)(21,4)(26,4) (26,0)(21,1)(16,3)(12,5)(8,8)(5,12)(3,16)(1,21)(0,26)(0,26) (3,26) .POL AT (9446,6118) BACKFILL <48 0 0 5 0 0 0> PNTS (26,22)(27,22)(21,22)(17,20)(14,19)(10,16)(7,12)(5,8)(3,5) (3,0)(0,0)(1,5)(3,9)(5,14)(8,17)(12,21)(16,23)(21,24)(26,25) (26,25)(26,22) .POL AT (9273,6094) PNTS (24,47)(29,47)(34,46)(37,44)(41,40)(44,37)(46,33)(48,29)(48,24) (48,19)(46,15)(44,11)(41,7)(37,4)(34,2)(29,1)(24,0)(19,1)(15,2) (11,4)(7,7)(4,11)(3,15)(1,19)(0,24)(1,29)(3,33)(4,37)(7,40) (11,44)(15,46)(19,47)(24,47) .POL AT (9297,6118) BACKFILL <1 0 0 5 0 0 0> PNTS (22,0)(23,0)(22,5)(21,8)(19,12)(16,16)(13,19)(9,20)(5,22)(0,22) (0,25)(5,24)(10,23)(14,21)(17,17)(21,14)(23,9)(25,5)(25,0) (25,0)(22,0) .POL AT (9297,6092) PNTS (0,4)(1,4)(5,4)(9,5)(13,8)(16,10)(19,14)(21,17)(22,21)(22,26) (25,26)(25,21)(23,16)(21,12)(17,8)(14,5)(10,3)(5,1)(0,0)(0,0) (0,4) .POL AT (9272,6092) PNTS (3,26)(4,26)(3,21)(4,17)(7,14)(9,10)(13,8)(16,5)(20,4)(25,4) (25,0)(20,1)(16,3)(12,5)(8,8)(4,12)(2,16)(1,21)(0,26)(0,26) (3,26) .POL AT (9272,6118) PNTS (25,22)(26,22)(20,22)(16,20)(13,19)(9,16)(7,12)(4,8)(3,5)(3,0) (0,0)(1,5)(2,9)(4,14)(8,17)(12,21)(16,23)(20,24)(25,25)(25,25) (25,22) .POL AT (9212,6094) BACKFILL <48 0 0 5 0 0 0> PNTS (23,47)(28,47)(33,46)(37,44)(40,40)(43,37)(46,33)(47,29)(47,24) (47,19)(46,15)(43,11)(40,7)(37,4)(33,2)(28,1)(23,0)(19,1)(15,2) (11,4)(7,7)(4,11)(2,15)(0,19)(0,24)(0,29)(2,33)(4,37)(7,40) (11,44)(15,46)(19,47)(23,47) .POL AT (9235,6118) BACKFILL <1 0 0 5 0 0 0> PNTS (23,0)(24,0)(23,5)(21,8)(19,12)(16,16)(13,19)(9,20)(5,22)(0,22) (0,25)(5,24)(10,23)(15,21)(18,17)(22,14)(23,9)(25,5)(26,0) (26,0)(23,0) .POL AT (9235,6092) PNTS (0,4)(1,4)(5,4)(9,5)(13,8)(16,10)(19,14)(21,17)(23,21)(23,26) (26,26)(25,21)(23,16)(22,12)(18,8)(15,5)(10,3)(5,1)(0,0)(0,0) (0,4) .POL AT (9210,6092) PNTS (3,26)(4,26)(3,21)(5,17)(7,14)(10,10)(14,8)(17,5)(21,4)(25,4) (25,0)(21,1)(16,3)(12,5)(8,8)(5,12)(2,16)(1,21)(0,26)(0,26) (3,26) .POL AT (9210,6118) PNTS (25,22)(26,22)(21,22)(17,20)(14,19)(10,16)(7,12)(5,8)(3,5) (3,0)(0,0)(1,5)(2,9)(5,14)(8,17)(12,21)(16,23)(21,24)(25,25) (25,25)(25,22) .POL AT (8976,5502) BACKFILL <48 0 0 5 0 0 0> PNTS (21,0)(18,0)(14,2)(10,3)(6,6)(3,9)(2,12)(0,15)(0,19)(0,603) (0,607)(2,610)(3,613)(6,617)(10,619)(14,621)(18,622)(21,622) (752,622)(756,622)(760,621)(764,619)(767,617)(770,613)(771,610) (773,607)(773,603)(773,19)(773,15)(771,12)(770,9)(767,6)(764,3) (760,2)(756,0)(752,0)(21,0) .POL AT (8974,5500) BACKFILL <1 0 0 5 0 0 0> PNTS (4,21)(5,21)(4,18)(5,15)(7,12)(9,8)(12,7)(16,5)(20,4)(23,4) (23,0)(20,1)(15,2)(11,4)(7,6)(4,10)(2,13)(1,17)(0,21)(0,21) (4,21) .POL AT (8974,5521) PNTS (4,584)(5,584)(4,0)(0,0)(0,584)(0,584)(4,584) .POL AT (8974,6105) PNTS (23,18)(24,18)(20,18)(16,16)(12,14)(9,13)(7,10)(5,6)(4,3)(4,0) (0,0)(1,4)(2,8)(4,11)(7,15)(11,18)(15,19)(20,21)(23,21)(23,21) (23,18) .POL AT (8997,6123) PNTS (731,0)(732,0)(0,0)(0,3)(731,3)(731,3)(731,0) .POL AT (9728,6105) PNTS (19,0)(20,0)(19,3)(18,6)(16,10)(14,13)(12,14)(8,16)(4,18)(0,18) (0,21)(4,21)(9,19)(13,18)(16,15)(19,11)(21,8)(23,4)(23,0)(23,0) (19,0) .POL AT (9747,5521) PNTS (0,0)(1,0)(0,584)(4,584)(4,0)(4,0)(0,0) .POL AT (9728,5500) PNTS (0,4)(1,4)(4,4)(8,5)(12,7)(14,8)(16,12)(18,15)(19,18)(19,21) (23,21)(23,17)(21,13)(19,10)(16,6)(13,4)(9,2)(4,1)(0,0)(0,0) (0,4) .POL AT (8997,5500) PNTS (0,4)(1,4)(731,4)(731,0)(0,0)(0,0)(0,4) .POL AT (9069,5576) PNTS (4,17)(5,17)(4,15)(4,12)(6,10)(8,8)(10,6)(12,5)(15,4)(18,4) (18,0)(15,1)(11,2)(8,3)(5,5)(4,8)(1,11)(0,14)(0,17)(0,17)(4,17) .POL AT (9069,5593) PNTS (4,440)(5,440)(4,0)(0,0)(0,440)(0,440)(4,440) .POL AT (9069,6033) PNTS (18,13)(19,13)(15,13)(12,12)(10,11)(8,10)(6,7)(4,5)(4,3)(4,0) (0,0)(0,3)(1,7)(4,9)(5,12)(8,14)(11,15)(15,16)(18,17)(18,17) (18,13) .POL AT (9087,6046) PNTS (551,0)(552,0)(0,0)(0,4)(551,4)(551,4)(551,0) .POL AT (9638,6033) PNTS (15,0)(16,0)(15,3)(14,5)(13,7)(11,10)(9,11)(7,12)(4,13)(0,13) (0,17)(4,16)(7,15)(11,14)(13,12)(15,9)(17,7)(18,3)(19,0)(19,0) (15,0) .POL AT (9653,5593) PNTS (0,0)(1,0)(0,440)(4,440)(4,0)(4,0)(0,0) .POL AT (9638,5576) PNTS (0,4)(1,4)(4,4)(7,5)(9,6)(11,8)(13,10)(14,12)(15,15)(15,17) (19,17)(18,14)(17,11)(15,8)(13,5)(11,3)(7,2)(4,1)(0,0)(0,0) (0,4) .POL AT (9087,5576) PNTS (0,4)(1,4)(551,4)(551,0)(0,0)(0,0)(0,4) .POL AT (9086,5591) BACKFILL <53 0 0 5 0 0 0> PNTS (16,0)(13,0)(9,0)(7,2)(5,4)(3,6)(2,8)(1,11)(0,13)(0,431)(1,433) (2,436)(3,438)(5,441)(7,442)(9,444)(13,445)(16,445)(538,445) (541,445)(544,444)(547,442)(549,441)(551,438)(552,436)(553,433) (553,431)(553,13)(553,11)(552,8)(551,6)(549,4)(547,2)(544,0) (541,0)(538,0)(16,0) .POL AT (9084,5588) BACKFILL <1 0 0 5 0 0 0> PNTS (4,16)(5,16)(4,14)(5,12)(7,10)(8,7)(10,7)(12,5)(15,4)(18,4) (18,0)(15,1)(11,2)(8,3)(5,5)(4,8)(2,11)(1,13)(0,16)(0,16)(4,16) .POL AT (9084,5604) PNTS (4,418)(5,418)(4,0)(0,0)(0,418)(0,418)(4,418) .POL AT (9084,6022) PNTS (18,12)(19,12)(15,12)(12,11)(10,10)(8,9)(7,6)(5,4)(4,2)(4,0) (0,0)(1,3)(2,6)(4,8)(5,11)(8,13)(11,14)(15,15)(18,16)(18,16) (18,12) .POL AT (9102,6034) PNTS (522,0)(523,0)(0,0)(0,4)(522,4)(522,4)(522,0) .POL AT (9624,6022) PNTS (14,0)(15,0)(14,2)(13,4)(11,6)(10,9)(8,10)(6,11)(3,12)(0,12) (0,16)(3,15)(6,14)(10,13)(12,11)(14,8)(16,6)(17,3)(18,0)(18,0) (14,0) .POL AT (9638,5604) PNTS (0,0)(1,0)(0,418)(4,418)(4,0)(4,0)(0,0) .POL AT (9624,5588) PNTS (0,4)(1,4)(3,4)(6,5)(8,7)(10,7)(11,10)(13,12)(14,14)(14,16) (18,16)(17,13)(16,11)(14,8)(12,5)(10,3)(6,2)(3,1)(0,0)(0,0) (0,4) .POL AT (9102,5588) PNTS (0,4)(1,4)(522,4)(522,0)(0,0)(0,0)(0,4) END .GRP END PICTURE NOTES .GRP BACKFILL <34 2 5 1000 0 0 0> LINEFILL <21 21 5 1000 0 0 0> SHADOW <11 0 15 15> THICKNESS 1 FONT 2 .TMP AT (250,250) RECOLOR ON TEMPLATE_FLAGS <5 14 0 0> T_POS <250 250 7249 4875> .VOID .TMP AT (250,5125) RECOLOR ON TEMPLATE_FLAGS <6 15 0 0> T_POS <250 5125 7249 9749> .VOID END .GRP END NOTES SLIDE_INFO SLIDE_STYLE <0 -1 1> LAYOUT_ID <1 2 12 12 12> END SLIDE_INFO PICTURE .TMP AT (105,85) RECOLOR ON TEMPLATE_FLAGS <1 0 0 0> T_POS <105 85 9892 1504> .TXT AT (339,222) RECOLOR ON TEMPLATED ON BACKFILL <7 7 0 0 0 0 0> V_SPACE <0 611 0> SIZE 440000 BOLD ON HOR_JUST CENTER L_SPACE 611 MARGINS <0 0 0 0> TXTXYOFF <-130 448> T_PNTS (-5,446)(-5,-2)(9488,-2)(9488,1187)(-5,1187)(-5,446)(9488,446) H_SPACE 9788 .STR "Digital Certificates can solve the man-in-the-middle problem" .TMP AT (105,1562) RECOLOR ON TEMPLATE_FLAGS <2 3 0 0> T_POS <105 1562 9892 7370> .TXT AT (53,1646) RECOLOR ON TEMPLATED ON BACKFILL <20 20 0 0 0 0 0> PARA <-500 500 -500 1 1000 0 3 108> V_SPACE <333 444 0> SIZE 320000 BOLD OFF HOR_JUST LEFT L_SPACE 444 TXTXYOFF <13 322> T_PNTS (-2,320)(-2,-2)(9132,-2)(9132,4970)(-2,4970)(-2,320)(9132,320) .STR "Problem: I have no prior knowledge of the remote side's key" .STR "\nBut someone I trust can check who they are" .STR "\nThe trusted third party can vouch for the remote side by sign ing a certificate which contains the remote side's name and publ ic key" .STR "\nI can check the validity of the certificate using the trusted third party's public key" END PICTURE NOTES .GRP BACKFILL <34 2 5 1000 0 0 0> PARA <0 0 0 0 1000 1 0 111> V_SPACE <0 250 0> SIZE 180000 L_SPACE 250 MARGINS <125 125 250 62> .TMP AT (250,250) RECOLOR ON TEMPLATE_FLAGS <5 14 0 0> T_POS <250 250 7249 4875> .VOID .TMP AT (250,5125) RECOLOR ON TEMPLATE_FLAGS <6 15 0 0> T_POS <250 5125 7249 9749> .VOID END .GRP END NOTES SLIDE_INFO SLIDE_STYLE <0 -1 1> LAYOUT_ID <1 2 12 12 12> END SLIDE_INFO PICTURE .TMP AT (105,85) RECOLOR ON TEMPLATE_FLAGS <1 0 0 0> T_POS <105 85 9892 1504> .TXT AT (455,218) RECOLOR ON TEMPLATED ON BACKFILL <7 7 0 0 0 0 0> V_SPACE <0 611 0> SIZE 440000 BOLD ON HOR_JUST CENTER L_SPACE 611 MARGINS <0 0 0 0> TXTXYOFF <-130 448> T_PNTS (-1,445)(-1,-3)(9259,-3)(9259,1187)(-1,1187)(-1,445)(9259,445) .STR "Example: TLS (SSL) web server with digital certificate" .TMP AT (105,1562) RECOLOR ON TEMPLATE_FLAGS <2 3 0 0> T_POS <105 1562 9892 7370> .TXT AT (61,1658) RECOLOR ON TEMPLATED ON BACKFILL <20 20 0 0 0 0 0> PARA <-500 500 -500 1 1000 0 3 108> V_SPACE <333 444 0> SIZE 320000 BOLD OFF HOR_JUST LEFT L_SPACE 444 TXTXYOFF <13 317> T_PNTS (-5,315)(-5,-2)(9232,-2)(9232,5743)(-5,5743)(-5,315)(9232,315) .STR "I generate a private key on my webserver" .STR "\nI send my public key plus my identify (my webserver's domain name) to a certificate authority (CA)" .STR "\nThe CA manually checks that I am who I say I am, i.e. I own t he domain" .STR "\nThey sign a certificate containing my public key, my domain n ame, and an expiration date (Q: why is an expiration date includ ed?)" .STR "\nI install the certificate on my web server" END PICTURE NOTES .GRP BACKFILL <34 2 5 1000 0 0 0> PARA <0 0 0 0 1000 1 0 111> V_SPACE <0 250 0> SIZE 180000 L_SPACE 250 MARGINS <125 125 250 62> .TMP AT (250,250) RECOLOR ON TEMPLATE_FLAGS <5 14 0 0> T_POS <250 250 7249 4875> .VOID .TMP AT (250,5125) RECOLOR ON TEMPLATE_FLAGS <6 15 0 0> T_POS <250 5125 7249 9749> .VOID END .GRP END NOTES SLIDE_INFO SLIDE_STYLE <0 -1 1> LAYOUT_ID <1 2 12 12 12> END SLIDE_INFO PICTURE .TMP AT (105,85) RECOLOR ON TEMPLATE_FLAGS <1 0 0 0> T_POS <105 85 9892 1504> .TXT AT (835,230) RECOLOR ON TEMPLATED ON BACKFILL <7 7 0 0 0 0 0> V_SPACE <0 611 0> SIZE 440000 BOLD ON HOR_JUST CENTER L_SPACE 611 MARGINS <0 0 0 0> TXTXYOFF <-86 437> T_PNTS (-2,433)(-2,-4)(8456,-4)(8456,1058)(-2,1058)(-2,433)(8456,433) .STR "When a client's web browser connects to me with HTTPS:" .TMP AT (105,1562) RECOLOR ON TEMPLATE_FLAGS <2 3 0 0> T_POS <105 1562 9892 7370> .TXT AT (61,1658) RECOLOR ON TEMPLATED ON BACKFILL <20 20 0 0 0 0 0> PARA <-500 500 -500 1 1000 0 3 108> V_SPACE <333 444 0> SIZE 320000 BOLD OFF HOR_JUST LEFT L_SPACE 444 TXTXYOFF <13 317> T_PNTS (-5,315)(-5,-2)(9235,-2)(9235,4965)(-5,4965)(-5,315)(9235,315) .STR "They negotiate an encrypted session with me, during which they learn my public key" .STR "\nI send them the certificate" .STR "\nThey verify the certificate using the CA's public key, which is built-in to the browser" .STR "\nIf the certificate is valid, the domain name in the URL match es the domain name in the certificate, and the expiration date h as not passed, they know the connection is secure" END PICTURE NOTES .GRP BACKFILL <34 2 5 1000 0 0 0> PARA <0 0 0 0 1000 1 0 111> V_SPACE <0 250 0> SIZE 180000 L_SPACE 250 MARGINS <125 125 250 62> .TMP AT (250,250) RECOLOR ON TEMPLATE_FLAGS <5 14 0 0> T_POS <250 250 7249 4875> .VOID .TMP AT (250,5125) RECOLOR ON TEMPLATE_FLAGS <6 15 0 0> T_POS <250 5125 7249 9749> .VOID END .GRP END NOTES SLIDE_INFO SLIDE_STYLE <0 -1 1> LAYOUT_ID <1 2 12 12 12> END SLIDE_INFO PICTURE .TMP AT (105,85) RECOLOR ON TEMPLATE_FLAGS <1 0 0 0> T_POS <105 85 9892 1504> .TXT AT (264,218) RECOLOR ON TEMPLATED ON BACKFILL <7 7 0 0 0 0 0> V_SPACE <0 611 0> SIZE 440000 BOLD ON HOR_JUST CENTER L_SPACE 611 MARGINS <0 0 0 0> TXTXYOFF <-6 448> T_PNTS (-1,445)(-1,-3)(9368,-3)(9368,576)(-1,576)(-1,445)(9368,445) .STR "The security of TLS depends on:" .TMP AT (105,1562) RECOLOR ON TEMPLATE_FLAGS <2 3 0 0> T_POS <105 1562 9892 7370> .TXT AT (53,1651) RECOLOR ON TEMPLATED ON BACKFILL <20 20 0 0 0 0 0> PARA <-500 500 -500 1 1000 0 3 108> V_SPACE <333 444 0> SIZE 320000 BOLD OFF HOR_JUST LEFT L_SPACE 444 TXTXYOFF <13 317> T_PNTS (-2,315)(-2,-2)(8841,-2)(8841,5566)(-2,5566)(-2,315)(8841,315) .STR "Your webserver being secure" .STR PARA <-500 1000 -500 1 1000 0 3 108> V_SPACE <28 389 0> SIZE 280000 "\n\tSo nobody else can obtain your private key" .STR PARA <-500 500 -500 1 1000 0 3 108> V_SPACE <333 444 0> SIZE 320000 "\nThe CA's public key being in all browsers" .STR "\nThe CA being well managed" .STR PARA <-500 1000 -500 1 1000 0 3 108> V_SPACE <28 389 0> SIZE 280000 "\n\tHow carefully do they look after their own private keys?" .STR PARA <-500 500 -500 1 1000 0 3 108> V_SPACE <333 444 0> SIZE 320000 "\nThe CA being trustworthy" .STR PARA <-500 1000 -500 1 1000 0 3 108> V_SPACE <28 389 0> SIZE 280000 "\n\tDo they vet all certificate requests properly?" .STR "\n\tCould a hacker persuade the CA to sign their key pretending to be someone else? What about a government?" END PICTURE NOTES .GRP BACKFILL <34 2 5 1000 0 0 0> PARA <0 0 0 0 1000 1 0 111> V_SPACE <0 250 0> SIZE 180000 L_SPACE 250 MARGINS <125 125 250 62> .TMP AT (250,250) RECOLOR ON TEMPLATE_FLAGS <5 14 0 0> T_POS <250 250 7249 4875> .VOID .TMP AT (250,5125) RECOLOR ON TEMPLATE_FLAGS <6 15 0 0> T_POS <250 5125 7249 9749> .VOID END .GRP END NOTES SLIDE_INFO SLIDE_STYLE <0 -1 1> LAYOUT_ID <1 2 12 12 12> END SLIDE_INFO PICTURE .TMP AT (105,85) RECOLOR ON TEMPLATE_FLAGS <1 0 0 0> T_POS <105 85 9892 1504> .TXT AT (1221,222) RECOLOR ON TEMPLATED ON BACKFILL <7 7 0 0 0 0 0> V_SPACE <0 611 0> SIZE 440000 BOLD ON HOR_JUST CENTER L_SPACE 611 MARGINS <0 0 0 0> TXTXYOFF <-46 448> T_PNTS (0,446)(0,-2)(7564,-2)(7564,460)(0,460)(0,446)(7564,446) .STR "PGP takes a different view" .TMP AT (105,1562) RECOLOR ON TEMPLATE_FLAGS <2 3 0 0> T_POS <105 1562 9892 7370> .TXT AT (51,1641) RECOLOR ON TEMPLATED ON BACKFILL <20 20 0 0 0 0 0> PARA <-500 500 -500 1 1000 0 3 108> V_SPACE <333 444 0> SIZE 320000 BOLD OFF HOR_JUST LEFT L_SPACE 444 TXTXYOFF <13 322> T_PNTS (-5,320)(-5,-2)(8811,-2)(8811,5302)(-5,5302)(-5,320)(8811,320) .STR "We don't trust anyone except our friends (especially not big co rporate monopolies)" .STR "\nYou sign your friends' keys to vouch for them" .STR "\nOther people can choose to trust your signature as much as th ey trust you" .STR "\nGenerates a distributed \"web of trust\"" .STR "\nSign someone's key when you meet them face to face - \"PGP ke y signing parties\"" END PICTURE NOTES .GRP BACKFILL <34 2 5 1000 0 0 0> PARA <0 0 0 0 1000 1 0 111> V_SPACE <0 250 0> SIZE 180000 L_SPACE 250 MARGINS <125 125 250 62> .TMP AT (250,250) RECOLOR ON TEMPLATE_FLAGS <5 14 0 0> T_POS <250 250 7249 4875> .VOID .TMP AT (250,5125) RECOLOR ON TEMPLATE_FLAGS <6 15 0 0> T_POS <250 5125 7249 9749> .VOID END .GRP END NOTES SLIDE_INFO SLIDE_STYLE <0 -1 1> LAYOUT_ID <1 2 12 12 12> END SLIDE_INFO PICTURE .TMP AT (105,85) RECOLOR ON TEMPLATE_FLAGS <1 0 0 0> T_POS <105 85 9892 1504> .TXT AT (649,215) RECOLOR ON TEMPLATED ON BACKFILL <7 7 0 0 0 0 0> V_SPACE <0 611 0> SIZE 440000 BOLD ON HOR_JUST CENTER L_SPACE 611 MARGINS <0 0 0 0> TXTXYOFF <-107 448> T_PNTS (-3,447)(-3,-1)(8833,-1)(8833,1068)(-3,1068)(-3,447)(8833,447) .STR "SSH uses a simple solution to man-in-the-middle" .TMP AT (105,1562) RECOLOR ON TEMPLATE_FLAGS <2 3 0 0> T_POS <105 1562 9892 7370> .TXT AT (58,1648) RECOLOR ON TEMPLATED ON BACKFILL <20 20 0 0 0 0 0> PARA <-500 500 -500 1 1000 0 3 108> V_SPACE <333 444 0> SIZE 320000 BOLD OFF HOR_JUST LEFT L_SPACE 444 TXTXYOFF <13 322> T_PNTS (-6,320)(-6,-2)(9208,-2)(9208,5360)(-6,5360)(-6,320)(9208,320) .STR "The first time you connect to a remote host, remember its publi c key" .STR PARA <-500 1000 -500 1 1000 0 3 108> V_SPACE <28 389 0> SIZE 280000 "\n\tStored in ~/.ssh/known_hosts" .STR PARA <-500 500 -500 1 1000 0 3 108> V_SPACE <333 444 0> SIZE 320000 "\nThe next time you connect, if the remote key is different, th en maybe an attacker is intercepting the connection!" .STR PARA <-500 1000 -500 1 1000 0 3 108> V_SPACE <28 389 0> SIZE 280000 "\n\tOr maybe the remote host has just got a new key, e.g. after a reinstall. But it's up to you to resolve the problem" .STR PARA <-500 500 -500 1 1000 0 3 108> V_SPACE <333 444 0> SIZE 320000 "\nRelies on there being no attack in progress the " .STR ITALICS ON "first" .STR ITALICS OFF " time you connect to a machine" END PICTURE NOTES .GRP BACKFILL <34 2 5 1000 0 0 0> PARA <0 0 0 0 1000 1 0 111> V_SPACE <0 250 0> SIZE 180000 L_SPACE 250 MARGINS <125 125 250 62> .TMP AT (250,250) RECOLOR ON TEMPLATE_FLAGS <5 14 0 0> T_POS <250 250 7249 4875> .VOID .TMP AT (250,5125) RECOLOR ON TEMPLATE_FLAGS <6 15 0 0> T_POS <250 5125 7249 9749> .VOID END .GRP END NOTES SLIDE_INFO SLIDE_STYLE <0 -1 1> LAYOUT_ID <1 2 12 12 12> END SLIDE_INFO PICTURE .TMP AT (105,85) RECOLOR ON TEMPLATE_FLAGS <1 0 0 0> T_POS <105 85 9892 1504> .TXT AT (693,232) RECOLOR ON TEMPLATED ON BACKFILL <7 7 0 0 0 0 0> V_SPACE <0 611 0> SIZE 440000 BOLD ON HOR_JUST CENTER L_SPACE 611 MARGINS <0 0 0 0> TXTXYOFF <-23 448> T_PNTS (-2,446)(-2,-2)(8581,-2)(8581,576)(-2,576)(-2,446)(8581,446) .STR "SSH can eliminate passwords" .TMP AT (105,1562) RECOLOR ON TEMPLATE_FLAGS <2 3 0 0> T_POS <105 1562 9892 7370> .TXT AT (63,1658) RECOLOR ON TEMPLATED ON BACKFILL <20 20 0 0 0 0 0> PARA <-500 500 -500 1 1000 0 3 108> V_SPACE <333 444 0> SIZE 320000 BOLD OFF HOR_JUST LEFT L_SPACE 444 TXTXYOFF <13 317> T_PNTS (-2,315)(-2,-2)(8871,-2)(8871,5691)(-2,5691)(-2,315)(8871,315) .STR "Use public-key cryptography to prove who you are" .STR "\nGenerate a public/private key pair locally" .STR PARA <-500 1000 -500 1 1000 0 3 108> V_SPACE <28 389 0> SIZE 280000 "\n\tssh-keygen -t dsa" .STR "\n\tPrivate key is ~/.ssh/id_dsa" .STR "\n\tPublic key is ~/.ssh/id_dsa.pub" .STR PARA <-500 500 -500 1 1000 0 3 108> V_SPACE <333 444 0> SIZE 320000 "\nInstall your PUBLIC key on remote hosts" .STR PARA <-500 1000 -500 1 1000 0 3 108> V_SPACE <28 389 0> SIZE 280000 "\n\tmkdir .ssh" .STR "\n\tchmod 755 .ssh" .STR "\n\tCopy public key into ~/.ssh/authorized_keys" .STR PARA <-500 500 -500 1 1000 0 3 108> V_SPACE <333 444 0> SIZE 320000 "\nLogin!" END PICTURE NOTES .GRP BACKFILL <34 2 5 1000 0 0 0> PARA <0 0 0 0 1000 1 0 111> V_SPACE <0 250 0> SIZE 180000 L_SPACE 250 MARGINS <125 125 250 62> .TMP AT (250,250) RECOLOR ON TEMPLATE_FLAGS <5 14 0 0> T_POS <250 250 7249 4875> .VOID .TMP AT (250,5125) RECOLOR ON TEMPLATE_FLAGS <6 15 0 0> T_POS <250 5125 7249 9749> .VOID END .GRP END NOTES SLIDE_INFO SLIDE_STYLE <0 -1 1> LAYOUT_ID <1 2 12 12 12> END SLIDE_INFO PICTURE .TMP AT (105,85) RECOLOR ON TEMPLATE_FLAGS <1 0 0 0> T_POS <105 85 9892 1504> .TXT AT (845,228) RECOLOR ON TEMPLATED ON BACKFILL <7 7 0 0 0 0 0> V_SPACE <0 611 0> SIZE 440000 BOLD ON HOR_JUST CENTER L_SPACE 611 MARGINS <0 0 0 0> TXTXYOFF <-43 448> T_PNTS (-2,445)(-2,-3)(8267,-3)(8267,459)(-2,459)(-2,445)(8267,445) .STR "Notes on SSH authentication" .TMP AT (105,1562) RECOLOR ON TEMPLATE_FLAGS <2 3 0 0> T_POS <105 1562 9892 7370> .TXT AT (68,1661) RECOLOR ON TEMPLATED ON BACKFILL <20 20 0 0 0 0 0> PARA <-500 500 -500 1 1000 0 3 108> V_SPACE <333 444 0> SIZE 320000 BOLD OFF HOR_JUST LEFT L_SPACE 444 TXTXYOFF <13 317> T_PNTS (-6,315)(-6,-2)(9027,-2)(9027,5650)(-6,5650)(-6,315)(9027,315) .STR "Private key is protected by a passphrase" .STR PARA <-500 1000 -500 1 1000 0 3 108> V_SPACE <28 389 0> SIZE 280000 "\n\tSo you have to give it each time you log in" .STR "\n\tOr use \"ssh-agent\" which holds a copy of your passphrase in RAM" .STR PARA <-500 500 -500 1 1000 0 3 108> V_SPACE <333 444 0> SIZE 320000 "\nNo need to change passwords across dozens of machines" .STR "\nDisable passwords entirely!" .STR PARA <-500 1000 -500 1 1000 0 3 108> V_SPACE <28 389 0> SIZE 280000 "\n\t/etc/ssh/sshd_config" .STR PARA <-500 500 -500 1 1000 0 3 108> V_SPACE <333 444 0> SIZE 320000 "\nAnnoyingly, for historical reasons there are *three* differen t types of SSH key" .STR PARA <-500 1000 -500 1 1000 0 3 108> V_SPACE <28 389 0> SIZE 280000 "\n\tSSH1 RSA, SSH2 DSA, SSH2 RSA" END PICTURE NOTES .GRP BACKFILL <34 2 5 1000 0 0 0> PARA <0 0 0 0 1000 1 0 111> V_SPACE <0 250 0> SIZE 180000 L_SPACE 250 MARGINS <125 125 250 62> .TMP AT (250,250) RECOLOR ON TEMPLATE_FLAGS <5 14 0 0> T_POS <250 250 7249 4875> .VOID .TMP AT (250,5125) RECOLOR ON TEMPLATE_FLAGS <6 15 0 0> T_POS <250 5125 7249 9749> .VOID END .GRP END NOTES SLIDE_INFO SLIDE_STYLE <0 -1 1> LAYOUT_ID <1 2 12 12 12> END SLIDE_INFO PICTURE .TMP AT (105,85) RECOLOR ON TEMPLATE_FLAGS <1 0 0 0> T_POS <105 85 9892 1504> .TXT AT (412,234) RECOLOR ON TEMPLATED ON BACKFILL <7 7 0 0 0 0 0> V_SPACE <0 611 0> SIZE 440000 BOLD ON HOR_JUST CENTER L_SPACE 611 MARGINS <0 0 0 0> TXTXYOFF <-129 437> T_PNTS (-1,434)(-1,-3)(9351,-3)(9351,1176)(-1,1176)(-1,434)(9351,434) .STR "Designing a good cryptosystem is very difficult" .TMP AT (105,1562) RECOLOR ON TEMPLATE_FLAGS <2 3 0 0> T_POS <105 1562 9892 7370> .TXT AT (53,1646) RECOLOR ON TEMPLATED ON BACKFILL <20 20 0 0 0 0 0> PARA <-500 500 -500 1 1000 0 3 108> V_SPACE <333 444 0> SIZE 320000 BOLD OFF HOR_JUST LEFT L_SPACE 444 TXTXYOFF <13 322> T_PNTS (-2,320)(-2,-2)(8805,-2)(8805,5746)(-2,5746)(-2,320)(8805,320) .STR "Many possible weaknesses and types of attack, often not obvious " .STR "\nDON'T design your own!" .STR "\nDO use expertly-designed cryptosystems which have been subjec t to widespread scrutiny" .STR "\nUnderstand how they work and where the potential weaknesses a re" .STR "\nRemember the other weaknesses in your systems, especially the human ones" END PICTURE NOTES .GRP BACKFILL <34 2 5 1000 0 0 0> PARA <0 0 0 0 1000 1 0 111> V_SPACE <0 250 0> SIZE 180000 L_SPACE 250 MARGINS <125 125 250 62> .TMP AT (250,250) RECOLOR ON TEMPLATE_FLAGS <5 14 0 0> T_POS <250 250 7249 4875> .VOID .TMP AT (250,5125) RECOLOR ON TEMPLATE_FLAGS <6 15 0 0> T_POS <250 5125 7249 9749> .VOID END .GRP END NOTES SLIDE_INFO SLIDE_STYLE <0 -1 1> LAYOUT_ID <1 2 12 12 12> END SLIDE_INFO PICTURE .TMP AT (105,85) RECOLOR ON TEMPLATE_FLAGS <1 0 0 0> T_POS <105 85 9892 1504> .TXT AT (1037,219) RECOLOR ON TEMPLATED ON BACKFILL <7 7 0 0 0 0 0> V_SPACE <0 611 0> SIZE 440000 BOLD ON HOR_JUST CENTER L_SPACE 611 MARGINS <0 0 0 0> TXTXYOFF <-87 437> T_PNTS (0,437)(0,0)(8010,0)(8010,1179)(0,1179)(0,437)(8010,437) .STR "Where can you apply these cryptographic methods?" .TMP AT (105,1562) RECOLOR ON TEMPLATE_FLAGS <2 3 0 0> T_POS <105 1562 9892 7370> .TXT AT (35,1630) RECOLOR ON TEMPLATED ON BACKFILL <20 20 0 0 0 0 0> PARA <-500 500 -500 1 1000 0 3 108> V_SPACE <333 444 0> SIZE 320000 BOLD OFF HOR_JUST LEFT L_SPACE 444 TXTXYOFF <11 317> T_PNTS (0,317)(0,0)(9175,0)(9175,5624)(0,5624)(0,317)(9175,317) .STR "At the link layer" .STR PARA <-500 1000 -500 1 1000 0 3 108> V_SPACE <28 389 0> SIZE 280000 "\n\tPPP encryption" .STR PARA <-500 500 -500 1 1000 0 3 108> V_SPACE <333 444 0> SIZE 320000 "\nAt the network layer" .STR PARA <-500 1000 -500 1 1000 0 3 108> V_SPACE <28 389 0> SIZE 280000 "\n\tIPSEC" .STR PARA <-500 500 -500 1 1000 0 3 108> V_SPACE <333 444 0> SIZE 320000 "\nAt the transport layer" .STR PARA <-500 1000 -500 1 1000 0 3 108> V_SPACE <28 389 0> SIZE 280000 "\n\t" .STR "TLS (SSL): many applications support it" .STR PARA <-500 500 -500 1 1000 0 3 108> V_SPACE <333 444 0> SIZE 320000 "\nAt the application layer" .STR PARA <-500 1000 -500 1 1000 0 3 108> V_SPACE <28 389 0> SIZE 280000 "\n\tSSH: system administration, file transfers" .STR "\n\tPGP/GPG: for securing E-mail messages, stand-alone document s, software packages etc." .STR "\n\tTripwire (and others): system integrity checks" END PICTURE NOTES .GRP BACKFILL <34 2 5 1000 0 0 0> PARA <0 0 0 0 1000 1 0 111> V_SPACE <0 250 0> SIZE 180000 L_SPACE 250 MARGINS <125 125 250 62> .TMP AT (250,250) RECOLOR ON TEMPLATE_FLAGS <5 14 0 0> T_POS <250 250 7249 4875> .VOID .TMP AT (250,5125) RECOLOR ON TEMPLATE_FLAGS <6 15 0 0> T_POS <250 5125 7249 9749> .VOID END .GRP END NOTES *END GRAPHICS