*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" Sun May 5 14:59:47 2002 ** "Last Modified Version" 4.42 (1021.500) FONT "Times" "Zapf Dingbats" "Swiss" "Morewingbats" "Dutch" END FONT SESSION WIN_SIZE <7494 4307> 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 <1 506 506 -2406 -506> 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 (3826,237) 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 <-21 448> T_PNTS (0,448)(0,0)(2375,0)(2375,581)(0,581)(0,448)(2375,448) H_SPACE 9788 .STR "Security" .TMP AT (105,1562) RECOLOR ON TEMPLATE_FLAGS <1 2 0 0> T_POS <105 1562 9892 7370> .TXT AT (2081,1713) RECOLOR ON TEMPLATED ON TXTXYOFF <1 448> T_PNTS (0,448)(0,0)(5822,0)(5822,577)(0,577)(0,448)(5822,448) .STR "AFNOG 3 Workshop" END PICTURE NOTES .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 1 111> V_SPACE <0 250 0> FONT 0 SIZE 180000 BOLD OFF HOR_JUST LEFT 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 (1599,237) 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> PARA <0 0 0 0 1000 1 0 111> V_SPACE <0 611 0> FONT 2 SIZE 440000 BOLD ON HOR_JUST CENTER L_SPACE 611 MARGINS <0 0 0 0> TXTXYOFF <-41 448> T_PNTS (0,448)(0,0)(6869,0)(6869,581)(0,581)(0,448)(6869,448) .STR "Main Security Concerns" .TMP AT (105,1562) RECOLOR ON TEMPLATE_FLAGS <2 3 0 0> T_POS <105 1562 9892 7370> .TXT AT (81,1669) 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 (0,326)(0,0)(9142,0)(9142,5599)(0,5599)(0,326)(9142,326) .STR "Confidentiality" .STR PARA <-500 1000 -500 1 1000 0 3 108> V_SPACE <28 389 0> SIZE 280000 "\n\tKeeping our data safe from prying eyes" .STR PARA <-500 500 -500 1 1000 0 3 108> V_SPACE <333 444 0> SIZE 320000 "\n" .STR "Integrity" .STR PARA <-500 1000 -500 1 1000 0 3 108> V_SPACE <28 389 0> SIZE 280000 "\n\tProtecting our data from loss or unauthorised alteration" .STR PARA <-500 500 -500 1 1000 0 3 108> V_SPACE <333 444 0> SIZE 320000 "\n" .STR "Authentication and Authorisation" .STR PARA <-500 1000 -500 1 1000 0 3 108> V_SPACE <28 389 0> SIZE 280000 "\n\tIs this person who they claim to be?" .STR "\n\tIs this person allowed to do this?" .STR PARA <-500 500 -500 1 1000 0 3 108> V_SPACE <333 444 0> SIZE 320000 "\nAvailability" .STR PARA <-500 1000 -500 1 1000 0 3 108> V_SPACE <28 389 0> SIZE 280000 "\n\tAre our systems working when we need them? (Denial of Servi ce)" 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 (1308,237) 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 <-37 448> T_PNTS (0,448)(0,0)(7432,0)(7432,1192)(0,1192)(0,448)(7432,448) .STR "Security Implications of connecting to the Internet" .TMP AT (105,1562) RECOLOR ON TEMPLATE_FLAGS <2 3 0 0> T_POS <105 1562 9892 7370> .TXT AT (77,1668) 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 <15 324> T_PNTS (0,324)(0,0)(9243,0)(9243,4465)(0,4465)(0,324)(9243,324) .STR "The Internet lets you connect to millions of hosts" .STR PARA <-500 1000 -500 1 1000 0 3 108> V_SPACE <28 389 0> SIZE 280000 "\n\tbut they can also connect to you!" .STR PARA <-500 500 -500 1 1000 0 3 108> V_SPACE <333 444 0> SIZE 320000 "\nMany points of access (e.g. telephone, X25)" .STR PARA <-500 1000 -500 1 1000 0 3 108> V_SPACE <28 389 0> SIZE 280000 "\n\teven if you can trace an attack to a point on the Internet, the real source may be untraceable" .STR PARA <-500 500 -500 1 1000 0 3 108> V_SPACE <333 444 0> SIZE 320000 "\nYour host runs many Internet services" .STR PARA <-500 1000 -500 1 1000 0 3 108> V_SPACE <28 389 0> SIZE 280000 "\n\tmany potential points of vulnerability" .STR "\n\tmany servers run as \"root\" !" 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 (1714,241) 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 <-41 436> T_PNTS (0,436)(0,0)(6556,0)(6556,448)(0,448)(0,436)(6556,436) .STR "Network-based attacks" .TMP AT (105,1562) RECOLOR ON TEMPLATE_FLAGS <2 3 0 0> T_POS <105 1562 9892 7370> .TXT AT (57,1654) 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 <15 318> T_PNTS (0,318)(0,0)(8879,0)(8879,5182)(0,5182)(0,318)(8879,318) .STR "Passive attacks" .STR PARA <-500 1000 -500 1 1000 0 3 108> V_SPACE <28 389 0> SIZE 280000 "\n\te.g. packet sniffers, traffic analysis" .STR PARA <-500 500 -500 1 1000 0 3 108> V_SPACE <333 444 0> SIZE 320000 "\nActive attacks" .STR PARA <-500 1000 -500 1 1000 0 3 108> V_SPACE <28 389 0> SIZE 280000 "\n\te.g. connection hijacking, IP source spoofing, exploitation of weaknesses in IP stack or applications" .STR PARA <-500 500 -500 1 1000 0 3 108> V_SPACE <333 444 0> SIZE 320000 "\nDenial of Service attacks" .STR PARA <-500 1000 -500 1 1000 0 3 108> V_SPACE <28 389 0> SIZE 280000 "\n\te.g. synflood" .STR PARA <-500 500 -500 1 1000 0 3 108> V_SPACE <333 444 0> SIZE 320000 "\nAttacks against the network itself" .STR PARA <-500 1000 -500 1 1000 0 3 108> V_SPACE <28 389 0> SIZE 280000 "\n\te.g. smurf" 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 (1709,229) 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 (0,448)(0,0)(6545,0)(6545,462)(0,462)(0,448)(6545,448) .STR "Other common attacks" .TMP AT (105,1562) RECOLOR ON TEMPLATE_FLAGS <2 3 0 0> T_POS <105 1562 9892 7370> .TXT AT (61,1652) 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 <15 324> T_PNTS (0,324)(0,0)(8320,0)(8320,3599)(0,3599)(0,324)(8320,324) .STR "Brute-force and Dictionary attacks (password guessing)" .STR "\nViruses" .STR "\nTrojan horses" .STR "\nHumans are often the weakest link" .STR PARA <-500 1000 -500 1 1000 0 3 108> V_SPACE <28 389 0> SIZE 280000 "\n\t\"Hi, this is Bob, what's the root 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 (1060,245) 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 <0 436> T_PNTS (0,436)(0,0)(7817,0)(7817,448)(0,448)(0,436)(7817,436) .STR "Authentication: Passwords" .TMP AT (105,1562) RECOLOR ON TEMPLATE_FLAGS <2 3 0 0> T_POS <105 1562 9892 7370> .TXT AT (81,1669) 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 (0,326)(0,0)(8695,0)(8695,2775)(0,2775)(0,326)(8695,326) .STR "Can be guessed" .STR "\nIf too complex, users tend to write them down" .STR "\nIf sent unencrypted, can be \"sniffed\" from the network and re-used" 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 (1111,241) 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 (0,448)(0,0)(7762,0)(7762,581)(0,581)(0,448)(7762,448) .STR "Choosing good passwords" .TMP AT (105,1562) RECOLOR ON TEMPLATE_FLAGS <2 3 0 0> T_POS <105 1562 9892 7370> .TXT AT (77,1666) 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 <15 326> T_PNTS (0,326)(0,0)(8336,0)(8336,2805)(0,2805)(0,326)(8336,326) .STR "Combinations of upper and lower-case letters, numbers and symbo ls" .STR PARA <-500 1000 -500 1 1000 0 3 108> V_SPACE <28 389 0> SIZE 280000 "\n\t" .STR "'brute force' attacker has to try many more combinations" .STR PARA <-500 500 -500 1 1000 0 3 108> V_SPACE <333 444 0> SIZE 320000 "\nNot in any dictionary, including hackers dictionaries" .TXT AT (1192,5129) 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 L_SPACE 333 TXTXYOFF <0 254> T_PNTS (0,254)(0,0)(7176,0)(7176,1660)(0,1660)(0,254)(7176,254) H_SPACE 0 .STR L_SPACE 250 "$40&yc4f\n\"Money for nothing and your chicks for free\"\n\nwsR !vst?\n\"workshop students aRe not very sleepy today ?\"" 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 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 (1262,233) 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 <-84 448> T_PNTS (0,448)(0,0)(7604,0)(7604,1071)(0,1071)(0,448)(7604,448) H_SPACE 9788 .STR "Authentication: Source IP address" .TMP AT (105,1562) RECOLOR ON TEMPLATE_FLAGS <2 3 0 0> T_POS <105 1562 9892 7370> .TXT AT (69,1660) 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 <15 324> T_PNTS (0,324)(0,0)(9093,0)(9093,5297)(0,5297)(0,324)(9093,324) .STR "Not verified by the network (since not used in datagram deliver y)" .STR "\nDatagrams are easily forged" .STR "\nTCP 3-way handshake gives some degree of protection, as long as you can't guess TCP sequence numbers" .STR PARA <-500 1000 -500 1 1000 0 3 108> V_SPACE <28 389 0> SIZE 280000 "\n\tLegitimate example: controlling SMTP relaying by source IP address" .STR PARA <-500 500 -500 1 1000 0 3 108> V_SPACE <333 444 0> SIZE 320000 "\nAny UDP protocol is completely vulnerable" .STR PARA <-500 1000 -500 1 1000 0 3 108> V_SPACE <28 389 0> SIZE 280000 "\n\te.g. NFS" 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 (1120,249) 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 <1 436> T_PNTS (0,436)(0,0)(7715,0)(7715,448)(0,448)(0,436)(7715,436) .STR "Authentication: Host name" .TMP AT (105,1562) RECOLOR ON TEMPLATE_FLAGS <2 3 0 0> T_POS <105 1562 9892 7370> .TXT AT (81,1677) 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 <13 318> T_PNTS (0,318)(0,0)(9282,0)(9282,5330)(0,5330)(0,318)(9282,318) .STR "Very weak" .STR "\nDNS is easily attacked (e.g. by loading false information int o cache)" .STR "\nSlight protection by ensuring that reverse and forward DNS ma tches" .STR PARA <-500 1000 -500 1 1000 0 3 108> V_SPACE <28 389 0> SIZE 280000 "\n\te.g. Connection received from 80.248.72.254" .STR "\n\tLookup 80.248.72.254 -> noc.ws.afnog.org" .STR "\n\tLookup noc.ws.afnog.org -> 80.248.72.254" .STR PARA <-500 500 -500 1 1000 0 3 108> V_SPACE <333 444 0> SIZE 320000 "\nThis is why many sites won't let you connect unless your forw ard and reverse matches" 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 (1575,233) 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 <-25 448> T_PNTS (0,448)(0,0)(6815,0)(6815,581)(0,581)(0,448)(6815,448) .STR "Cryptographic methods" .TMP AT (105,1562) RECOLOR ON TEMPLATE_FLAGS <2 3 0 0> T_POS <105 1562 9892 7370> .TXT AT (53,1642) 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 <15 326> T_PNTS (0,326)(0,0)(9243,0)(9243,4439)(0,4439)(0,326)(9243,326) .STR "Can provide REALLY SECURE solutions to authentication, privacy and integrity" .STR "\nSome are hard to implement, many different tools, usually req uires special clients" .STR "\nExport and usage restrictions (less of a problem these days)" .STR "\nTake care to understand where the weaknesses lie" 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 (1945,229) 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 (0,448)(0,0)(6078,0)(6078,577)(0,577)(0,448)(6078,448) .STR "Simple combinations" .TMP AT (105,1562) RECOLOR ON TEMPLATE_FLAGS <2 3 0 0> T_POS <105 1562 9892 7370> .TXT AT (82,1675) 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 <15 324> T_PNTS (0,324)(0,0)(8600,0)(8600,2328)(0,2328)(0,324)(8600,324) .STR "The lock on your front door can be picked" .STR "\nTwo locks are better than one" .STR "\nThe thief is more likely to try somewhere else" 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 (158,253) 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 <-39 436> T_PNTS (0,436)(0,0)(9657,0)(9657,1059)(0,1059)(0,436)(9657,436) .STR "IP source address AND password authentication" .TMP AT (105,1562) RECOLOR ON TEMPLATE_FLAGS <2 3 0 0> T_POS <105 1562 9892 7370> .TXT AT (73,1670) 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 <15 318> T_PNTS (0,318)(0,0)(9093,0)(9093,2852)(0,2852)(0,318)(9093,318) .STR "You can use \"tcp wrappers\" (/etc/hosts.allow) to add IP sourc e authentication to any service run from inetd" .STR PARA <-500 1000 -500 1 1000 0 3 108> V_SPACE <28 389 0> SIZE 280000 "\n\tFor info and examples: man 5 hosts_access" .STR PARA <-500 500 -500 1 1000 0 3 108> V_SPACE <333 444 0> SIZE 320000 "\nThe application also typically has password authentication" 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 (3783,253) 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 <-45 436> T_PNTS (0,436)(0,0)(2438,0)(2438,448)(0,448)(0,436)(2438,436) .STR "Exercise" .TMP AT (105,1562) RECOLOR ON TEMPLATE_FLAGS <2 3 0 0> T_POS <105 1562 9892 7370> .TXT AT (73,1666) 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 <15 322> T_PNTS (0,322)(0,0)(9265,0)(9265,5722)(0,5722)(0,322)(9265,322) .STR "Enable telnet (note: bad idea!)" .STR PARA <-500 1000 -500 1 1000 0 3 108> V_SPACE <28 389 0> SIZE 280000 "\n\tUncomment telnet ... tcp line in /etc/inetd.conf" .STR "\n\tkillall -1 inetd" .STR "\n\tCheck other people can telnet to your machine" .STR PARA <-500 500 -500 1 1000 0 3 108> V_SPACE <333 444 0> SIZE 320000 "\nNow restrict access to only yourself and your neighbour" .STR PARA <-500 1000 -500 1 1000 0 3 108> V_SPACE <28 389 0> SIZE 280000 "\n\tAdd two lines to top of /etc/hosts.allow" .STR "\n\ttelnetd : 80.248.72.12, 80.248.72.11 : allow" .STR "\n\ttelnetd : ALL : deny" .STR PARA <-500 500 -500 1 1000 0 3 108> V_SPACE <333 444 0> SIZE 320000 "\nGet someone on a different row to try to telnet to you. What happens if you telnet to 127.0.0.1 ?" 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 (225,237) 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 <-43 448> T_PNTS (0,448)(0,0)(9521,0)(9521,581)(0,581)(0,448)(9521,448) .STR "UNDERSTAND what you're doing" .TMP AT (105,1562) RECOLOR ON TEMPLATE_FLAGS <2 3 0 0> T_POS <105 1562 9892 7370> .TXT AT (77,1674) 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 <15 318> T_PNTS (0,318)(0,0)(8662,0)(8662,5710)(0,5710)(0,318)(8662,318) .STR "A bad security solution is worse than no security at all" .STR "\nKnow what you're doing" .STR PARA <-500 1000 -500 1 1000 0 3 108> V_SPACE <28 389 0> SIZE 280000 "\n\tRead all the documentation" .STR "\n\tRead sample configurations" .STR "\n\tBuild test machines" .STR "\n\tAsk questions" .STR "\n\tJoin the announcements mailing list for your O/S and applic ations" .STR PARA <-500 500 -500 1 1000 0 3 108> V_SPACE <333 444 0> SIZE 320000 "\nTest what you've done" .STR PARA <-500 1000 -500 1 1000 0 3 108> V_SPACE <28 389 0> SIZE 280000 "\n\tTry connecting from outside your network" .STR "\n\tTry circumventing your own rules" 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 (3626,241) 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 (0,448)(0,0)(2748,0)(2748,581)(0,581)(0,448)(2748,448) .STR "Summary" .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 <15 318> T_PNTS (0,318)(0,0)(9249,0)(9249,4411)(0,4411)(0,318)(9249,318) .STR "Disable all services which are not needed" .STR "\nApply security patches promptly; join the announcement mailin g lists" .STR "\nGood password management" .STR "\nCombine passwords with IP access controls where possible" .STR "\nUse cryptographic methods where possible" 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 (1478,237) 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 <-25 448> T_PNTS (0,448)(0,0)(6983,0)(6983,581)(0,581)(0,448)(6983,448) .STR "Cryptographic methods:" .TMP AT (105,1562) RECOLOR ON TEMPLATE_FLAGS <1 2 0 0> T_POS <105 1562 9892 7370> .TXT AT (2676,1725) RECOLOR ON TEMPLATED ON TXTXYOFF <-3 436> T_PNTS (0,436)(0,0)(4612,0)(4612,2403)(0,2403)(0,436)(4612,436) .STR "Three important\ncomponents of\ncryptographic\nsystems" .TXT AT (2071,6256) 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 <1 239> T_PNTS (0,239)(0,0)(5679,0)(5679,647)(0,647)(0,239)(5679,239) H_SPACE 0 .STR L_SPACE 250 "Recommended reading:\n\"Applied Cryptography\", Bruce Schnier" 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 <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 (518,253) 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 <-128 436> T_PNTS (0,436)(0,0)(9153,0)(9153,1176)(0,1176)(0,436)(9153,436) H_SPACE 9788 .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 (395,4583) 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 <-11 239> T_PNTS (0,239)(0,0)(701,0)(701,577)(0,577)(0,239)(701,239) H_SPACE 0 .STR L_SPACE 250 "clear\ntext" .TXT AT (8887,4585) RECOLOR ON L_SPACE 333 T_PNTS (0,239)(0,0)(701,0)(701,577)(0,577)(0,239)(701,239) .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 (2144,4867) 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)(282,0)(282,477)(0,477)(0,476)(282,476) .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 (7393,4869) 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)(282,0)(282,477)(0,477)(0,476)(282,476) .STR L_SPACE 250 "k" .TXT AT (4276,3839) RECOLOR ON BACKFILL <7 20 5 1000 0 0 0> V_SPACE <0 333 0> SIZE 240000 BOLD ON L_SPACE 333 TXTXYOFF <-11 239> T_PNTS (0,239)(0,0)(980,0)(980,579)(0,579)(0,239)(980,239) .STR L_SPACE 250 "cipher\ntext" .TXT AT (747,6199) RECOLOR ON BACKFILL <20 20 5 1000 0 0 0> V_SPACE <0 417 0> SIZE 300000 BOLD OFF L_SPACE 417 TXTXYOFF <-1 298> T_PNTS (0,298)(0,0)(8594,0)(8594,806)(0,806)(0,298)(8594,298) .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 (454,249) 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 <-88 436> T_PNTS (0,436)(0,0)(9229,0)(9229,1176)(0,1176)(0,436)(9229,436) 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 (81,1669) 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 (0,326)(0,0)(7519,0)(7519,423)(0,423)(0,326)(7519,326) .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 (469,251) 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 <-43 438> T_PNTS (0,438)(0,0)(9066,0)(9066,571)(0,571)(0,438)(9066,438) .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 (69,1658) 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 <15 326> T_PNTS (0,326)(0,0)(9148,0)(9148,5303)(0,5303)(0,326)(9148,326) .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 (621,251) 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 <-43 438> T_PNTS (0,438)(0,0)(8760,0)(8760,571)(0,571)(0,438)(8760,438) .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 (81,1671) 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 <13 324> T_PNTS (0,324)(0,0)(8966,0)(8966,5334)(0,5334)(0,324)(8966,324) .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 (1684,245) 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 <-96 436> T_PNTS (0,436)(0,0)(6782,0)(6782,1180)(0,1180)(0,436)(6782,436) .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 (395,4583) 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 <-11 239> T_PNTS (0,239)(0,0)(701,0)(701,577)(0,577)(0,239)(701,239) H_SPACE 0 .STR L_SPACE 250 "clear\ntext" .TXT AT (610,5694) RECOLOR ON V_SPACE <0 417 0> SIZE 300000 L_SPACE 417 TXTXYOFF <1 298> T_PNTS (0,298)(0,0)(8994,0)(8994,1225)(0,1225)(0,298)(8994,298) .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 (6168,4148) 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 <1 239> T_PNTS (0,239)(0,0)(2531,0)(2531,647)(0,647)(0,239)(2531,239) .STR L_SPACE 250 "Fixed length\n\"message digest\"" .TXT AT (2827,4253) RECOLOR ON BOLD ON L_SPACE 333 TXTXYOFF <0 239> T_PNTS (0,239)(0,0)(1291,0)(1291,579)(0,579)(0,239)(1291,239) .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 (3615,253) 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 <-43 436> T_PNTS (0,436)(0,0)(2776,0)(2776,565)(0,565)(0,436)(2776,436) 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 (65,1656) 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 <15 324> T_PNTS (0,324)(0,0)(9172,0)(9172,4862)(0,4862)(0,324)(9172,324) .STR "Unix crypt() function" .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 (2063,221) 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 <-21 448> T_PNTS (0,448)(0,0)(5817,0)(5817,1192)(0,1192)(0,448)(5817,448) .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 (61,1652) 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 <15 324> T_PNTS (0,324)(0,0)(9019,0)(9019,3309)(0,3309)(0,324)(9019,324) .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 (3779,245) 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 <-45 436> T_PNTS (0,436)(0,0)(2438,0)(2438,448)(0,448)(0,436)(2438,436) .STR "Exercise" .TMP AT (105,1562) RECOLOR ON TEMPLATE_FLAGS <2 3 0 0> T_POS <105 1562 9892 7370> .TXT AT (81,1677) 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 <13 318> T_PNTS (0,318)(0,0)(9243,0)(9243,5603)(0,5603)(0,318)(9243,318) .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/motd" .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 "\nmd5 /etc/motd" .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/motd and repeat the md5 test " .STR "\nUnder Linux the command is \"md5sum\"" 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 (447,225) 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 <0 448> T_PNTS (0,448)(0,0)(9038,0)(9038,1192)(0,1192)(0,448)(9038,448) .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 (81,1671) 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 <13 324> T_PNTS (0,324)(0,0)(9251,0)(9251,4969)(0,4969)(0,324)(9251,324) .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/master.passwd" .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" 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 (472,233) 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 (0,448)(0,0)(8986,0)(8986,1073)(0,1073)(0,448)(8986,448) .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 (81,1677) 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 <13 318> T_PNTS (0,318)(0,0)(9019,0)(9019,2081)(0,2081)(0,318)(9019,318) .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 (8304,4494) 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)(1440,0)(1440,377)(0,377)(0,367)(1440,367) H_SPACE 0 .STR L_SPACE 250 "Server" .TXT AT (95,4589) RECOLOR ON L_SPACE 500 TXTXYOFF <-23 367> T_PNTS (0,367)(0,0)(1242,0)(1242,379)(0,379)(0,367)(1242,367) .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 (4075,4343) 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)(1462,0)(1462,319)(0,319)(0,245)(1462,245) .STR L_SPACE 250 "Challenge" .TXT AT (2950,5110) RECOLOR ON L_SPACE 333 TXTXYOFF <-21 245> T_PNTS (0,245)(0,0)(3713,0)(3713,319)(0,319)(0,245)(3713,245) .STR L_SPACE 250 "hash(Challenge + Secret)" .TXT AT (1146,5937) 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)(7426,0)(7426,1150)(0,1150)(0,306)(7426,306) .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 (1648,249) 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 <-126 436> T_PNTS (0,436)(0,0)(6853,0)(6853,1059)(0,1059)(0,436)(6853,436) 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 (77,1666) 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 <15 326> T_PNTS (0,326)(0,0)(9140,0)(9140,4107)(0,4107)(0,326)(9140,326) .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 (622,229) 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 (0,448)(0,0)(8701,0)(8701,1192)(0,1192)(0,448)(8701,448) .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 (59,1668) 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 <15 318> T_PNTS (0,318)(0,0)(9243,0)(9243,4963)(0,4963)(0,318)(9243,318) .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 break. English text is typically only 1.3 bi ts of randomness per character." .TXT AT (588,6743) 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)(8848,0)(8848,736)(0,736)(0,245)(8848,245) .STR L_SPACE 444 "http://www.cranfield.ac.uk/docs/email/pgp/pgp-attack-faq.txt \n http://www.counterpane.com/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 (1002,237) 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 <-25 448> T_PNTS (0,448)(0,0)(7966,0)(7966,581)(0,581)(0,448)(7966,448) .STR "Generating encryption keys" .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 (1654,3051) 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 <-27 239> T_PNTS (0,239)(0,0)(1711,0)(1711,909)(0,909)(0,239)(1711,239) H_SPACE 0 .STR L_SPACE 250 "Passphrase\nentered by\nuser" .TXT AT (6247,3197) RECOLOR ON V_SPACE <0 417 0> SIZE 300000 L_SPACE 417 TXTXYOFF <-37 298> T_PNTS (0,298)(0,0)(1224,0)(1224,806)(0,806)(0,298)(1224,298) .STR L_SPACE 250 "128-bit\nkey" .TXT AT (4379,3851) RECOLOR ON V_SPACE <0 333 0> SIZE 240000 BOLD ON L_SPACE 333 TXTXYOFF <1 239> T_PNTS (0,239)(0,0)(752,0)(752,579)(0,579)(0,239)(752,239) .STR L_SPACE 250 "MD5\nhash" .TXT AT (2083,5941) RECOLOR ON V_SPACE <0 417 0> SIZE 300000 BOLD OFF L_SPACE 417 TXTXYOFF <-31 298> T_PNTS (0,298)(0,0)(5592,0)(5592,806)(0,806)(0,298)(5592,298) .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 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 (1702,233) 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 (0,448)(0,0)(6538,0)(6538,1188)(0,1188)(0,448)(6538,448) H_SPACE 9788 .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 (81,1669) 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 (0,326)(0,0)(3120,0)(3120,1200)(0,1200)(0,326)(3120,326) .STR "S/Key (OPIE)" .STR "\nCryptocard" 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 (1563,225) 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 <1 448> T_PNTS (0,448)(0,0)(6814,0)(6814,1192)(0,1192)(0,448)(6814,448) .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 (69,1660) 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 <15 324> T_PNTS (0,324)(0,0)(9075,0)(9075,2441)(0,2441)(0,324)(9075,324) .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 (1701,249) 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 <-13 436> T_PNTS (0,436)(0,0)(6563,0)(6563,569)(0,569)(0,436)(6563,436) .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 (393,3583) 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 <-11 239> T_PNTS (0,239)(0,0)(701,0)(701,577)(0,577)(0,239)(701,239) H_SPACE 0 .STR L_SPACE 250 "clear\ntext" .TXT AT (8885,3587) RECOLOR ON L_SPACE 333 T_PNTS (0,239)(0,0)(701,0)(701,575)(0,575)(0,239)(701,239) .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 (990,3857) 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)(2498,0)(2498,1356)(0,1356)(0,476)(2498,476) .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 (6144,3863) 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)(2691,0)(2691,1356)(0,1356)(0,476)(2691,476) .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 (4274,2839) 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 <-11 239> T_PNTS (0,239)(0,0)(980,0)(980,579)(0,579)(0,239)(980,239) .STR L_SPACE 250 "cipher\ntext" .TXT AT (1150,5938) RECOLOR ON BACKFILL <20 20 5 1000 0 0 0> V_SPACE <0 417 0> SIZE 300000 BOLD OFF L_SPACE 417 TXTXYOFF <-19 306> T_PNTS (0,306)(0,0)(7602,0)(7602,814)(0,814)(0,306)(7602,306) .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 (1212,253) 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 <-43 436> T_PNTS (0,436)(0,0)(7596,0)(7596,569)(0,569)(0,436)(7596,436) 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 (73,1670) 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 <15 318> T_PNTS (0,318)(0,0)(9097,0)(9097,5411)(0,5411)(0,318)(9097,318) .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 (870,239) 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 <0 438> T_PNTS (0,438)(0,0)(8196,0)(8196,1182)(0,1182)(0,438)(8196,438) .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 (393,3583) 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 <-11 239> T_PNTS (0,239)(0,0)(701,0)(701,577)(0,577)(0,239)(701,239) H_SPACE 0 .STR L_SPACE 250 "clear\ntext" .TXT AT (8885,3587) RECOLOR ON L_SPACE 333 T_PNTS (0,239)(0,0)(701,0)(701,575)(0,575)(0,239)(701,239) .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 (887,3846) 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)(2691,0)(2691,1356)(0,1356)(0,476)(2691,476) .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 (6236,3855) 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 <0 476> T_PNTS (0,476)(0,0)(2499,0)(2499,1356)(0,1356)(0,476)(2499,476) .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 (4274,2839) 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 <-11 239> T_PNTS (0,239)(0,0)(980,0)(980,579)(0,579)(0,239)(980,239) .STR L_SPACE 250 "cipher\ntext" .TXT AT (581,5935) 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)(8705,0)(8705,1227)(0,1227)(0,302)(8705,302) .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 (1314,253) 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 <-45 436> T_PNTS (0,436)(0,0)(7388,0)(7388,569)(0,569)(0,436)(7388,436) H_SPACE 9788 .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 (77,1668) 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 <15 324> T_PNTS (0,324)(0,0)(9154,0)(9154,5307)(0,5307)(0,324)(9154,324) .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 (1314,253) 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 <-45 436> T_PNTS (0,436)(0,0)(7388,0)(7388,569)(0,569)(0,436)(7388,436) .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 (2196,2635) 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)(1544,0)(1544,1093)(0,1093)(0,357)(1544,357) 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 (905,5049) 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 <-27 239> T_PNTS (0,239)(0,0)(1711,0)(1711,909)(0,909)(0,239)(1711,239) .STR L_SPACE 250 "Passphrase\nentered by\nuser" .TXT AT (7033,2714) RECOLOR ON V_SPACE <0 500 0> L_SPACE 333 TXTXYOFF <1 357> T_PNTS (0,357)(0,0)(1001,0)(1001,1027)(0,1027)(0,357)(1001,357) .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 (3725,5842) RECOLOR ON V_SPACE <0 250 0> SIZE 180000 BOLD ON L_SPACE 250 TXTXYOFF <-15 179> T_PNTS (0,179)(0,0)(551,0)(551,183)(0,183)(0,179)(551,179) .STR "hash" .TXT AT (4618,2403) RECOLOR ON TXTXYOFF <-7 179> T_PNTS (0,179)(0,0)(1233,0)(1233,484)(0,484)(0,179)(1233,179) .STR "symmetric\ncipher" .TXT AT (5391,4376) RECOLOR ON TXTXYOFF <-15 179> T_PNTS (0,179)(0,0)(401,0)(401,234)(0,234)(0,179)(401,179) .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 <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 (3310,253) 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 <-45 436> T_PNTS (0,436)(0,0)(3382,0)(3382,569)(0,569)(0,436)(3382,436) 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 (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 <15 318> T_PNTS (0,318)(0,0)(9146,0)(9146,3745)(0,3745)(0,318)(9146,318) .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 "\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 (178,249) 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 <-43 436> T_PNTS (0,436)(0,0)(9639,0)(9639,1176)(0,1176)(0,436)(9639,436) .STR "Public key cryptosystems require a lot of computation" .TMP AT (105,1562) RECOLOR ON TEMPLATE_FLAGS <2 3 0 0> T_POS <105 1562 9892 7370> .TXT AT (81,1669) 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 (0,326)(0,0)(8142,0)(8142,868)(0,868)(0,326)(8142,326) .STR "So we use some tricks to minimise the amount of data which is e ncrypted" 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 (2421,245) 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 <-1 436> T_PNTS (0,436)(0,0)(5079,0)(5079,569)(0,569)(0,436)(5079,436) .STR "When encrypting:" .TMP AT (105,1562) RECOLOR ON TEMPLATE_FLAGS <2 3 0 0> T_POS <105 1562 9892 7370> .TXT AT (77,1676) 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 <15 318> T_PNTS (0,318)(0,0)(9217,0)(9217,1747)(0,1747)(0,318)(9217,318) .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 (2747,6853) 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)(465,0)(465,577)(0,577)(0,476)(465,476) 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 (6753,6857) 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)(546,577)(0,577)(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 (3816,5830) 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 <1 239> T_PNTS (0,239)(0,0)(1879,0)(1879,645)(0,645)(0,239)(1879,239) .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 (4249,4834) 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 <-11 239> T_PNTS (0,239)(0,0)(980,0)(980,579)(0,579)(0,239)(980,239) .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 (233,5486) 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 <5 239> T_PNTS (0,239)(0,0)(1895,0)(1895,645)(0,645)(0,239)(1895,239) .STR BACKFILL <1 20 5 1000 0 0 0> L_SPACE 250 "random\nsession key" .TXT AT (2443,4965) 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 <-29 357> T_PNTS (0,357)(0,0)(373,0)(373,462)(0,462)(0,357)(373,357) .STR V_SPACE <0 500 0> SIZE 360000 L_SPACE 250 "k" .STR SIZE 240000 SUBSUP <0 100> L_SPACE 667 "s" .TXT AT (7702,4980) RECOLOR ON V_SPACE <0 667 0> SIZE 480000 SUBSUP <0 0> T_PNTS (0,357)(0,0)(373,0)(373,462)(0,462)(0,357)(373,357) .STR V_SPACE <0 500 0> SIZE 360000 L_SPACE 250 "k" .STR SIZE 240000 SUBSUP <0 100> L_SPACE 667 "s" 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 SUBSUP <0 0> HOR_JUST LEFT 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 (1899,249) 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 <-1 436> T_PNTS (0,436)(0,0)(6124,0)(6124,569)(0,569)(0,436)(6124,436) 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 (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 <15 324> T_PNTS (0,324)(0,0)(8780,0)(8780,1311)(0,1311)(0,324)(8780,324) .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 (2745,6851) 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)(546,0)(546,577)(0,577)(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 (6751,6855) 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)(465,0)(465,577)(0,577)(0,476)(465,476) .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 (4101,5865) 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 <0 239> T_PNTS (0,239)(0,0)(1485,0)(1485,645)(0,645)(0,239)(1485,239) .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 (8154,5499) 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 <-11 245> T_PNTS (0,245)(0,0)(1667,0)(1667,253)(0,253)(0,245)(1667,245) .STR L_SPACE 250 "COMPARE" .TXT AT (2603,4664) RECOLOR ON BACKFILL <20 20 5 1000 0 0 0> V_SPACE <0 250 0> SIZE 180000 TXTXYOFF <-13 179> T_PNTS (0,179)(0,0)(551,0)(551,183)(0,183)(0,179)(551,179) .STR "hash" .TXT AT (7850,4648) RECOLOR ON T_PNTS (0,179)(0,0)(551,0)(551,183)(0,183)(0,179)(551,179) .STR "hash" 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 <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 (791,241) 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 <-128 448> T_PNTS (0,448)(0,0)(8612,0)(8612,1071)(0,1071)(0,448)(8612,448) 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 (81,1677) 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 <13 318> T_PNTS (0,318)(0,0)(9174,0)(9174,5801)(0,5801)(0,318)(9174,318) .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 (1069,253) 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 <-88 436> T_PNTS (0,436)(0,0)(8009,0)(8009,1180)(0,1180)(0,436)(8009,436) .STR "Where can you apply these cryptgraphic methods?" .TMP AT (105,1562) RECOLOR ON TEMPLATE_FLAGS <2 3 0 0> T_POS <105 1562 9892 7370> .TXT AT (73,1670) 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 <15 318> T_PNTS (0,318)(0,0)(4968,0)(4968,4376)(0,4376)(0,318)(4968,318) .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\tTLS (SSL)" .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, PGP/GPG" 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