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1. 7 t 13 QUXUTDZV 14 tor 14 FOCPOFMU 15 iii eds e 15 TVVIXVTC 16 e ef 16 FZVHUCDI 17 ore i 17 ZUUFRSTX 18 er 18 Now adding to the light in line 1 for lightning and line 16 17 suggests before will give enough to solve as the keyword is revealed Run again and select type 2 ENTER allows the built in example to be used and all screens and actions are as for type 1 With this ex 10 gt QUAGMIRE I AID MAY 1994 100 CLEAR KEY OFF COLOR 4 7 2 CLS pt pt Computer Supplement 21 3 PACS Mr ect Ma a at aaa e tr 3 Pt A AS hoe Saad O ees 4 Bid E EE sere ait eed e tr fg 5 Pt O seen ace cere Siac ae EEE 6 Pt he efgi n Mie craeienuak 1 Ch ae ee 7 pt 8 22991 Mew elena oe Ostreicas 8 ABCDEFGHI JKLMNOPQRSTUVWXYZ Col No CT letter S PT letter T ample four fits are found The correct one is No 2 To help get you into things quickly the plaintext begins acatusesits Be careful in inputting the letters it s cleart ext first then plaintext In the alphabet grids they are reversed for type 1 and 2 by G4EGG M 0 P 1 8 P 2 9 110 D 12345 AZ ABCDEFGHI JKLMNOPQRSTUVWXYZ T 1 pt T 2 ct 120 HD An aid to solving the QuagmireI and QuagmireII ciphers GOTO 900 198 subs start here 199 make patterns of text 200 FOR I 1 TO P P I 210 FOR J 0 TO CB 1 STEP P 220 P I P I MID C J I 1 230 NEXT 240 NEXT 250 FOR I 1
2. 1 TO Count ENDDO RETU APPE2 PRG Append records using a loop I tried adding an extra field to the Dict database that contained the length of the word and then used that field in the FOR con dition However I discovered that the fields used in the FOR expression must reside in the structure of both databases After giving up on the SET RELATION com mand the program would not append from an open database I believe that the APPE3 PRG program is the easiest and quickest way to ap proach the problem I have not compared the times for the three methods but I suspect that APPEND and COPY would each take less than the hour it took you originally After each database is created the MODI STRU command is used to match the length of the Word field to the name of the file i e Dict13 would have a field length of 13 and so on name e g Dict3 is length 4 AND SUBS Word Count 1 Length of WORD is the same as Dict name e g Dict3 is length 3 16 Computer Supplement 21 SET TALK OFF CREATE Dict APPE FROM WORDS TXT SDF STORE 3 TO Count DO WHILE Count lt 23 FileName DICT LTRIM STR Count 2 CREATE amp FileName STORE Count 1 TO Count ENDDO USE Dict STORE 1 TO Count DO WHILE NOT EOF NextWrd TRIM Word WordLen LEN NextWrd NewFile DICT LTRIM STR WordLen 2 USE amp NewFile APPE BLANK REPL Word WITH NextWrd STORE Count 1 TO Count USE Dict GO Count ENDDO RETU
3. 500 Put plaintext corresponding to cleartext into plaintext block Lines 600 800 Test letter spacing in alphabets and transfer similar spacing to other alphabets where let ters fit Also put newly determined letters in plaintext block Lines 400 725 1000 1010 1120 1180 1840 2400 and 2420 contain the code to direct type 1 or type 2 The programme is written in QuickBasic but to make it more compatible with other dialects line numbering has been maintained Two functions of QuickBasic that have been used may not be available in other dialects They are UCASE which converts a string to up per case and LCASE that does the opposite The classic method alternative for UCASE is nnn A qweRTYuio for Z 1 to LEN A MID A Z 1 CHR ASC MID A Z 1 AND 223 NEXT For LCASE MID part of the above becomes MID A Z 1 CHR ASC MID A Z 1 AND 223 32 2 Computer Supplement 21 To use the programme with the built in example When RUN comments on the use are given on screen and a request to select TYPE 1 or TYPE 2 Quagmire The screen will show An aid to solving the QuagmireI and QuagmireII ciphers G4EGG If input data is from a file the file name extension must be CT It is not necessary to enter the extension when giving file name Period may be from 4 to 9 Examination of both PT columns and alphabet grid should indicate more PT letters These are added by entering the PT col
4. CTRL BREAK will return to the program 220 Subroutine to reset old CTRL BREAK address 230 DEF SEG 0 240 FOR I amp H6C TO amp H6F 250 POKE I 0LD I amp H6C 260 NEXT 270 DEF SEG RETURN CTRL BREAK will interupt the program SCREEN Determine Monitor type 10 DEF SEG 0 20 MONITOR TYPE PEEK amp H410 AND amp H40 30 IF MONITOR TYPE 1 THEN PRINT 40 X 25 Color 40 IF MONITOR TYPE 32 THEN PRINT 80 X 25 Color 50 IF MONITOR TYPE 48 THEN PRINT Monochrome 60 IF MONITOR TYPE 64 THEN PRINT Both Spring 1996 31 Switch displays on a system with both monochrome and color graphics 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 Subroutine to switch to monochrome adaptor DEF SEG 0 POKE amp H410 PEEK amp H410 OR amp H30 SCREEN 0O gt restore screen to text mode WIDTH 80 gt restore screen width to 80 LOCATE 1 12 13 gt restore cursor to normal RETURN gt Subroutine to switch to color adaptor Change gt SCREEN and WIDTH statements for different modes DEF SEG 0 POKE amp H410 PEEK amp H410 AND amp HCF OR amp H10 SCREEN 1 0 0 0 gt Medium resolution graphics color active page 0 visual page 0 WIDTH 40 gt WIDTH 80 would force the screen to clear and set to SCREEN 2 for high resolution LOCATE 1 6 7 gt restore cursor to normal for color screen RETURN Subroutine to save and restore a screen image 100 110 120 130 100 101 102 103
5. UCASE PTL the examples DATA RGEESEDIZMYUXIZUXBRJSPLIXWYDSFWHDARDSTDGQYUF QUWWP JFGQOBXF JXEQGXX QKXLRFLBAERUIUWUFOXMFFWSXLJUSKXESO JHARVTQUXUTDZVFOCPOFMUTVV JXVTC FZVHUCDIZUUFRSTX DATA HOZUQJGOIEQUDAJINKUWS JROKGLNS JWGWUYZEJEBTPDTONHHGUI JVECMZWURITEGQ SAATOKOKMPPOFKAODMEGAMJTLEYSWMHUGPCVMBMEK JKEYCHODEF JGMSAAJIGIIWE UGLKJYDHJXMYIXYFFFPTYLG DATA EARTHMILESFROMTHE DATA MINEIFASPACEISTOOSM Computer Supplement 21 ENIGMA 95 Clarence E Tyner Jr Randall K Nichols A simulation of an enhanced Enigma Cipher Machine on a standard personal computer ABSTRACT An exploration into the possibilities of what can be done with the operating methods of the Enigma on the personal computer The same concept of employing keyboard input a plug board rotors both normal and reflecting Uhr box and visual output are used but are expanded by using 100 position rotors that in termittently rotate a prime amount after each input allowing the number of rotors to vary from 1 to 12 in front or backwards orientation top permit any keyboard character including spaces to be encrypted and to simultaneously display cipher and clear text for editing A ro tating Character Set converts single character input into 2 digit numbers for processing and superencipherment of numeric output into al pha bigrams is possible Regular rotors Re versing rotors Character Sets and Superenci pherment Tables are provided in sets of 100 for
6. e All issue disks expanded and ready to run o JATpX formatted Computer Supplement is sues from 16 to 21 e Various word lists and pattern dictionaries e Various utilities for IBM PC compatibles e Cryptographic items of historical interest e Random number generation and testing e General computer security documents and software e Various unprotects and password guessers Spring 1996 15 dBASE Additions Kenneth Madl Ed Ken Madl includes here some enhance ments to PARROT s dBASE routines from Computer Supplement 20 DMV Following are copies of three different meth ods to achieve the same result but without having to type the replacement routine 20 times I thought initially that I could sim ply use the command APPE FROM Dict FOR Count LEN TRIM Word but I discovered that dBASE seems to append the record then based on the FOR condition decide whether or not to accept it Thus every record was accepted into Dict3 since words larger than three characters were truncated to three I could only get around that limitation by mak ing the field length one character larger than the length of the word APPE1 PRG Append records using the APPEND command Length of WORD must be 1 larger than Dict CREATE Dict APPE FROM WORDS TXT SDF STORE 3 TO Count DO WHILE Count lt 23 FileName Dict LTRIM STR Count 2 CREATE amp FileName APPE FROM Dict for SUBS Word Count _ STORE Count
7. APPE3 PRG Append records using the COPY command Length of Word is reduced after records are entered CREATE Dict APPE FROM WORDS TXT SDF STORE 3 TO Count DO WHILE Count lt 23 FileName DICT LTRIM STR Count 2 COPY TO amp FileName FOR LEN TRIM Word Count USE amp FileName MODI STRU amp amp Reduce size of Word field USE Dict STORE Count 1 TO Count ENDDO RETU DEL BAK from DOS command line Spring 1996 17 An Introduction to Modern Cryptology Copyright G H Foot April 1996 Cryptography is the art of disguising a com munication of any nature and transmitted by any means in order that the information con veyed cannot be understood by anyone except the person for whom it is intended For this to be possible a secret understanding of some kind a Key must be arranged in advance be tween the parties concerned and must never be revealed to any other person The use of the Key enables the communication to be en crypted at the source and decrypted after its arrival Commonly the process involved in encrypting a textual message is to manipulate the charac ters so that the words become unrecognizable A great variety of methods have been adopted through the ages from the simple replacement of each character with the third character in the alphabet beyond it as used by Julius Cae sar to intricate arrangements of characters in columns rows and groups which have to be re arranged by the recipie
8. Any comments would appreciated AT THE CRYPTO DROP BOX The disk accompanying this article contains ENIGMA 95 and the necessary supporting files needed in its operation Also included are program files to create them and to analyze and test its operation DOC files are included for each file to explain them Start with CRYPTO 1ST then read ENIGMA95 DOC and study ENIGMA95 FLO to gain an understanding of Enigma 95 before running it The list of files is CRYPTO 15T ENIGMA95 DOC ENIGMA95 FLO An outline of the files that constitute Enigma 95 system Detailed documentation pertaining to ENIGMA95 A flowchart of the ENIGMA95 operation ENIGMA95 BAS ENIGMA95 ROTORS DAT Set of 100 Regular Rotors REVROTRS DAT Set of 100 Reversing Rotors CHARS DAT Set of 100 Character Sets CODE DAT Set of 100 Super Encipherment Tables CRYPT005 BAS Random Numbers Generator for CRYPTO27 amp CRYPTO34 CRYPTO27 BAS Regular Rotor Creation using the Interval Method CRYPT028 BAS Super Encipherment Tables Creation CRYPT030 BAS Character Set Creation CRYPTO34 BAS Reversing Rotor Creation CRYPT043 BAS ENIGMA95 Cipher Machine Data Paths Demonstrator CRYPTO45 BAS Rotors Matching Analysis CRYPT047 BAS Check of Rotor Files for Errors CRYPTO48 BAS Analysis of Cleartext vs Ciphertext CRYPT049 BAS Rotor Intermittent Movement Test CRYPTO51 BAS Plugboard Combinations ENIGMA95 WRI The article about Enigma 95 Created using Wi
9. How ever only non superenciphered numeric ci phertext messages have the following addi tional data provided 1 A Hash Total which is a Mod 100 sum of the numeric cipher text See Al B1 2 A set of Column Check Totals which is the Mod 100 sum of each of the 27 columns of cipher text This is followed by a non mod total of the columns See A2 A3 B2 3 A total of Row Check Totals which is the Mod 100 sum of each row of cipher text This is followed by a non mod total of the rows See A2 A3 B2 12 The purpose of providing column and row to tals is to be able to locate transmission gar bles They would be sent only if requested Variances in any given column and row would locate the error by intersection The Message in Transmission Form This is what would be sent and would con tain only the External Control Settings ro tor settings superencipherment table number and external checksum the date and time group the message ciphertext and the char acter count The External Control Settings would be disguised by a simple manual su perencipherment that would be administrative and outside the operation of the Enigma 95 i e prescribed by the SOI See A3 C2 If it is decryption the cleartext message is presented with normal horizontal spacing and vertically double spaced for convenient read ing See B3 D2 Optional Message Analysis This is simply a count of input and output characters This ca
10. 1023 DATA Printer DATA Breakpoint 1024 DATA Resident BASIC DATA Overflow 1025 DATA Bootstrap DATA Print Screen 1026 DATA Time of Day DATA Reserved 1027 DATA Keyboard Break DATA Reserved 1028 DATA Timer Tick DATA Time of Day 1029 DATA Video Parameters DATA Keyboard 1030 DATA Diskette Parameters DATA Reserved 1031 DATA Video Graphics Exten DATA Communications 1032 DATA DOS Program Term DATA Communications 1033 DATA DOS Function Call DATA Disk 1034 DATA DOS Terminate Addr DATA Diskette 1035 DATA DOS Ctrl Break Exit DATA Printer 1036 DATA DOS Fatal Error DATA Video 1037 DATA DOS Abs Disk Read DATA Equipment Check 1038 DATA DOS Abs Disk Write DATA Memory 1039 DATA DOS Terminate amp Fix DATA Diskette Disk 1256 END of program DATA Communications
11. 1130 IF CT lt gt F AND CT lt gt f THEN 1160 1140 PRINT INPUT Name of file holding data N I INSTR N IF I gt O THEN N LEFT N I 1 1150 N N CT OPEN I 1 N INPUT 1 CT CLOSE 1 PRINT CT 1160 I INSTR CT IF I gt O THEN CT LEFT CT I 1 MID CT I 1 GOTO 1160 1170 LOCATE 10 5 INPUT Enter crib CB IF CB THEN READ CB 1180 IF TYP 2 THEN READ CB 1790 I INSTR CB IF I gt O THEN CB LEFT CB I 1 MID CB I 1 GOTO 1790 1800 LOCATE 10 19 CB UCASE CB PRINT CB 1810 CT LEN CT CB LEN CB 1820 PRINT INPUT And period P 1840 IF P lt 4 OR P gt 9 THEN P P TYP 1850 LOCATE 12 18 PRINT LOCATE 12 18 PRINT P 1890 find pattern of crib 1900 C CB GOSUB 200 CPAT CBB 1940 step through CT and check pattern of parts length of crib 1950 FOR N 1 TO CT CB 1960 C MID CT N CB 1970 GOSUB 200 1980 IF CBB CPAT THEN M M 1 F M N F M C 1990 NEXT 2090 make columns of CT and grid for PT 2100 FOR I 1 TO P 2110 FOR J I TO CT STEP P 2120 CC I CC I MID CT J 1 2130 NEXT 2140 NEXT 2190 if more than one fit which to try 2200 IF M 1 THEN MM 1 GOTO 2250 2210 LOCATE 22 10 PRINT There are M positions that fit INPUT Which MM Spring 1996 2240 2250 2260 2265 2270 2280 2290 2300 2310 2390 2400 2410 2420
12. 39 READ NAM I NEXT I 146 FOR I 40 TO 63 NAM I Reserved for DOS NEXT I 148 NAM 64 Revector Diskette NAM 65 Fixed Disk Parms 150 FOR I 66 TO 95 NAM I Reserved NEXT I 152 FOR I 96 TO 103 NAM I User Interrupts NEXT I 34 154 156 158 160 165 170 180 190 200 210 220 230 240 250 260 270 280 290 300 310 320 330 340 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 Computer Supplement 21 FOR I 104 TO 127 NAM I Not Used NEXT I FOR I 128 TO 133 NAM I Reserved by BASIC NEXT I FOR I 134 TO 240 NAM I BASIC Interpreter NEXT I FOR I 241 TO 255 NAM I Not Used NEXT I REM OPEN LPT1 FOR OUTPUT AS 1 PRINT 1 FOR PAGE 1 TO 2 PRINT 1 CHR 12 TITLE TITLE FOR K PAGE 1 128 TO PAGE 1 128 64 1 I kK ADDRESS I 4 GOSUB 280 PRINT 1 I K 64 ADDRESS I 4 GOSUB 280 PRINT 1 NEXT K NEXT PAGE CLOSE 1 SYSTEM REM PRINT 1 FNJUSTIFY HEX I 2 PRINT 1 FNJUSTIFY HEX ADDRESS 4 PRINT 1 FNJUSTIFY HEX PEEK ADDRESS 2 PEEK ADDRESS 3 256 4 PRINT 1 FNJUSTIFY HEX PEEK ADDRESS 0 PEEK ADDRESS 1 256 4 PRINT 1 LEFT NAM I SPACE 20 20 RETURN REM DATA Divide by Zero 1021 DATA Cassette DATA Single Step 1022 DATA Keyboard DATA Nonmaskable
13. Set sp DEF LOC DEF SEG amp HB800 Save screen image INPUT Enter name of file FILENAME for color graphics BSAVE FILENAMES 0 amp H4000 display in text mode RETURN O INPUT Enter name of file FILENAME Restore image O CLS O DEF SEG amp HB800 gt Change DEF SEG amp HB800 O BLOAD FILENAME gt to amp HBOOO for monochrome lit screen scroll window starting on line X ending on line Y SEG POKE 91 X POKE 92 Y Sets up window ATE X C Place cursor in the scroll window at line X column C Set window width DEF SEG POKE 41 X Set window width to X 32 Computer Supplement 21 Set 16 background colors While WIDTH 40 OUT amp H3D8 8 While WIDTH 80 OUT amp H3D8 9 Use other than palate color 3 for characters in medium resolution DEF SEG POKE amp H4E COLOR COLOR may be 1 2 or 3 DISKETTE DRIVES Read drive switches DEF SEG 0 NUMBER OF DRIVES PEEK amp H410 AND amp HCO Current disk information DEF SEG 64 PEEK 69 Tracks PEEK 70 Heads PEEK 71 Sectors PEEK 72 Bytes per sector PRINTER Printer Status works with IBM Dot Matrix and Epson printers DEF SEG 64 A PEEK 8 256 PEEK 9 B INT A 1 AND 248 XOR 72 IF B AND 128 lt gt 128 THEN PRINTER STATUS 0FF LINE ELSE PRINTER STATUS 0N LINE Initialize Printer DEF SEG 64 A PEEK 8 256 PEEK 9 DEF SEG OUT A 2 8 OUT A 2 12 Spring 1996 33 MEMORY Determine amount of me
14. Shakespeare Contact him for printed materials and soft ware including the 4l page pamphlet Are there Ciphers in Shakespeare FAT DRAGON Daniel Killoran has scanned most of his 35 year collection of The Cryptogram into his computer in a form suit able for optical character recognition the for mat used by Caere s OmniPage Pro If this would be of any use to the Krewe they are welcome to it although it might be a little difficult to send over 400 megabytes BOATTAIL Patrick J Larkin has up graded to a Pentium 60MHz from his old 386 16 He has also upgraded his monitor to a Sony 15 inch SVGA His is now running Win dows for Workgroups 3 11 and is planning on upgrading further by adding a CD ROM and Windows 95 later on this year He hasn t done any programming for a long time but still uses his crypto programs to work on each issue of the Cryptogram He also continues to subscribe to the ACA L electronic mailing list COLD DUCK L Rucinski is interested in locating a copy of Caxton Foster s Crypt analysis for Microcomputers He is unable to locate a copy or even a telephone number or address for Hayden Books Any help would be appreciated FAT DRAGON Daniel Killoran has for his own use and convenience scanned most of his 35 year collection of The Cryptogram into his computer in a form suitable for opti cal character recognition the format used by Caere s OmniPage Pro If this would be of any us
15. TO P TW 1 TC 1 260 FOR J 1 TO LEN P I 270 A MID P I J 1 280 B INSTR P I A G4EGG 290 IF B gt O THEN MID P I B 1 MID D TW 1 GOTO 280 300 TW TW 1 310 NEXT 320 NEXT PRINT 330 CBB 340 FOR I 1 TO P CBB CBB P I NEXT 350 RETURN Spring 1996 390 400 405 410 412 416 418 420 430 440 450 460 470 480 490 500 590 600 610 620 630 640 650 660 670 680 690 700 710 720 725 730 740 750 760 770 780 790 800 890 900 910 920 930 940 950 gt put letters in alphabets grid IF TYP lt gt 2 THEN A INSTR AZ CTL IF A O THEN 500 MID RL CL A 1 LCASE PTL ELSE A INSTR AZ PTL IF A O THEN 500 MID RL CL A 1 LCASE CTL END IF LOCATE 4 CL 49 PRINT RL CL gt put them into PT block FOR L 1 TO LEN CC CL IF L gt 19 THEN L 99 GOTO 490 IF MID CC CL L 1 CTL THEN LOCATE 2 L 21 CL PRINT LCASE PTL END IF NEXT RETURN cross ref alphabets FOR RM 1 TO P LOCATE 4 RM 45 PRINT gt IF RM gt 1 THEN LOCATE 3 RM 45 PRINT FOR RS 1 TO P IF RS RM THEN GOTO 760 CL RS FOR II 1 TO 26 A MID RL RM II 1 IF A OR INSTR RL RS A O0 THEN 750 ARM II ARS INSTR RL RS A DIF II ARS FOR JJ 1 TO 26 S MID RL RM JJ 1 IF S OR INSTR RL RS S gt O THEN 740 SS JJ DIF IF SS lt 1 THEN SS SS 26 G
16. To get there take I 95 north or south de pending on where you live relative to Mary land and take the exit for Route 32 east in Maryland The exit will say Fort Meade and Columbia On Route 32 east go past route 295 There are signs on the road that point to the Museum you want to look on your left for a Shell gas station Immediately after the Shell station on your left is Colony 7 Road Take this road which brings you to the gas station you just saw and follow it right up to the NSA museum Its a little building sur rounded with an anchor link fence topped with barbed wire Open Weekdays except holidays Open Saturdays 10am 2pm Phone 301 688 5849 9am 3 pm The curator s name is Jack Ingram I went with two friends of mine One of our party a friend named Doug Stan ton had recovered some code books from a German U boat that was sunk off the coast of Rhode Island in the last days of WWII After 6 months of treatment the books came out in very readable condition Jack looked over these code books for some minutes and spec ulated on the possibility that an Enigma ma chine may still be on the U boat This U boat was sunk by depth charges so the crew never had a chance to surface and ditch the Enigma machine Unless they shot it out a torpedo tube it might still be on board buried under 3 feet of silt and who knows what else Jack estimates that if the Enigma is found and if it has a printer atta
17. be ing encrypted as itself e Allow a longer period between repeti tions e Permit superencipherment e Provide 100 position rotors and plug board which are more difficult to ana lyze 10 e Facilitate masking control elements in messages e g rotor settings etc This format required a method of converting input into 2 digit form It was done by creat ing what are called Character Sets These are randomly organized sets of 100 characters upper and lowercase that appear on the key board The entire 100 positions are not used and the unused are filled with a seldom used accent mark One hundred sets are available in a file on floppy disk The sets are used in both encryption and decryption to convert from and back to cleartext Using 100 as a common feature brought into use the digits 00 99 to identify rotors sets tables and plugboard positions Sets of these components have 100 of each 00 means 100 The next feature was to provide for the unique rotation or non rotation movement of each rotor is randomly intermittent of each regular and the reversing rotor after each input The Character Set also rotates so that doubles like oo in book are converted differently Rotation is by a prime amount to 100 2 and 5 are not used Editing prevents using other numbers An additional feature was to provide a Rotor Display similar to the windows on the Enigma This is primarily informational but has
18. because a Digital Signature has been attached to the message The most successful of the Public Key Cryp tosystems is that known as RSA named from its inventors Rivest Shamir and Adleman the mathematical basis of which is the great difficulty of factoring the product of two large prime numbers a problem studied by math ematicians for centuries without finding an easy solution Numbers which are hundreds Computer Supplement 21 of digits in length are used and considerable computing capacity is required However there are reservations concerning Public Key Cryptography in practice The distribution and especially the authentication of a large number of Public Keys throughout the world is a severe problem even more se vere is the problem of cancelling a Public Key if it has been distributed extensively but is no longer valid The loss of a Private Key can be announced falsely in order to repudiate a con tractual liability and other mispractices can arise an illustration that a sound technical solution is insufficient to ensure that a cryp tosystem is suitable for general use even if it may be excellent in a specialized application One other practical problem confronts RSA The computing power necessary for its appli cation is considerable so that even if the com puters available are adequate in capacity the speed of operation may be unacceptably slow A class of hybrid systems has therefore arisen in which RSA
19. extensive variety Visual monitor display and paper printout are employed and other con trols are provided It is a what if specula tion that shows what could have been possible if the technology had been available Everyone is familiar with the Enigma Cipher Machine and the way it operates However the more you learn about it and read about the cryptanalysis that overcame it in World War II the more you wonder if it could be improved without becoming impossibly com plicated The personal computer provides a means to improve the concepts that made the original Enigma work and it can make it work much better This project started as a simulation of the original Enigma The pathway of the electric circuit caused by pressing a key is easy to un derstand It goes from the keyboard through the plugboard to the rotors is reflected from the reversing rotor back through the rotors through the plugboard and finally to a lamp that lights under a round window with an al phabet on it At least one rotor will rotate during the pressing of the key and the path way through the rotors will change from what it was previously The internal wiring of the rotors is random and the cumulative circuit offset combinations produce an extensive num ber of substitution alphabets The plugboard adds to this as did the Uhr box Aside from administrative and operator er rors the weaknesses of the enigma were as fol lows 1 The internal w
20. of cu riosity I tried simple substitution transposi tion a few other things including an Enigma simulator program and of course Caesar I seemed to get no positive result so I left it alone When the ciphertext reappeared as the sub ject of the contest I reapplied my efforts to its solution Vigenere seemed the most likely can didate but after a couple of days of this and a number of other blind alleys I was still no fur ther ahead After all I thought I had tried all of the easy tracks already Simultaneously I had been reading the book dwelling heav ily on the first chapter where according to the publisher the clue to the solution lay If so it was not evident to me However in one of the book s later chapters the central character has trouble deciphering a number of Enigma messages until he realises that the output is not in German as expected but is a list of Polish names I had gone to bed that evening still thinking about the con test cipher At about six in the morning I awoke with the thought It s not in English Rushing to the computer I tried the simplest thing Caesar And there it was in Latin I had had the answer for several weeks and had overlooked it All that remained was to get a confirmation of the translation into colloquial English Any Latin that I had been exposed to had gone in the forty plus years since my schooldays Who did I know with a knowledge of Latin an
21. proven to be helpful in de bugging the program and it does provide a sense of rotor movement Another idea was borrowed from Mr Hebern That was the ability to insert rotors into the machine either forwards or backwards which doubles the number of rotors in a given set It was also possible to provide for a variable number of rotors An arbitrary limit of 12 was chosen but it would be possible to have more though that might be considered overkill The important thing here is that it would be possible to employ from 1 to 12 rotors from a set of 100 depending on the security desired The rotor display automatically adjusts to the selected number Computer Supplement 21 The next feature that was added was the abil ity to optionally superencipher the resulting numeric ciphertext This involves replacing a 2 digit numeric cipher with a 2 character al phabetic bigram e g 36 to HK It also per mits each numeric cipher to be represented by one of 6 or 7 bigrams e g 36 could be HK UM RY AU ZM or BI The 7th bigram appears only for selected numerics because the 676 26 x 26 possible bigrams are evenly distributed amongst the 100 numerics In addition the use of a given bigram in a set for each nu meric is incremented sequentially so using this example the numeric 36 would be converted to HK the first time it appears to UM the sec ond time etc The first selection can start at any of the first 6 positions and
22. 2430 2440 2450 2460 2470 2480 2490 2500 2510 2520 2590 2600 2610 2620 2630 2635 2640 2650 2660 2670 2680 2690 2699 2700 2750 2800 2850 gt print columns of CT and grid for PT CLS PRINT TAB 10 HD LOCATE 3 1 K 0 IF CT P gt 19 THEN NR 19 ELSE NR INT CT P 9 FOR I 1 TO NR K K 1 PRINT Ws FOR J 1 TO P PRINT MID CC J I 1 NEXT LOCATE 19 PRINT USING K PRINT STRING P K NEXT gt print grid for alphabets LOCATE 4 43 PRINT T 3 TYP s AZ FOR I 1 TO P RL I STRING 26 LOCATE 4 I 43 PRINT T TYP I RL I I NEXT LOCATE 4 I 49 PRINT AZ gt put crib into PT block and alphabet grids Y1 INT F MM P X1 F MM Y1 P FOR Ii O TO CB 1 CL X1 I1 MOD P IF CL O THEN CL P CTL MID F MM I1 1 1 PTL MID CB I1 1 1 GOSUB 400 NEXT CL 99 GOTO 2620 gt get new letters from keyboard LOCATE 16 56 PRINT LOCATE 16 47 INPUT Col No CL IF CL O THEN 2670 IF CL 99 THEN GOSUB 600 GOTO 2600 IF CL gt 99 THEN GOTO 2200 IF CL gt P THEN 2600 LOCATE 17 47 INPUT CT letter CTL CTL LOCATE 18 47 INPUT PT letter PTL PTL GOSUB 400 GOTO 2600 LOCATE 22 30 INPUT Done N ew crib R un again or M enu Z IF Z M OR Z m THEN RUN MENU BAS IF Z R OR Z r THEN RUN ELSE RESTORE 2700 CLS GOTO 1170 UCASE CTL
23. 3 Not used Bit 14 15 Number of printers attached e amp H13 Memory Size in K bytes e amp H15 I O RAM Size in K bytes e amp H17 Keyboard Flag the following lists the masks set to describe current keyboard status Byte 1 amp H80 Insert state active amp H40 Caps Lock State Has been toggled amp H20 Num Lock State has been toggled Spring 1996 amp H10 Scroll Lock State has been toggled amp HOS8 Alternate Shift key de pressed amp HO4 Control Shift key depressed amp HO2 Left Shift key depressed amp HO1 Right Shift key depressed Byte 2 amp H80 Insert Key is depressed amp H40 Caps Lock Key is depressed amp H20 Num Lock Key is depressed amp H10 Scroll Lock key is depressed amp HO8 Suspend key has been tog gled e amp H49 Current CRT mode amp HOO 40x25 BW amp HO1 40x25 Color amp HO2 80x25 BW amp HO3 80x25 Color amp HO4 320x200 Color amp HO5 320x200 BW amp HO6 640x200 BW amp HO7 80x25 B amp W Card spe cialized use used internally by the video routines amp H4A Number of CRT columns amp H50 Cursor Position one of eight amp H60 Current cursor mode amp H6C Low word of Timer count amp H6E High word of Timer count 29 e amp H71 amp HO7 Break key depressed e amp HFA6E Beginning of character regen memory e amp HFF53 Pr
24. ASIC or Pascal and almost all executables are for IBM PC compatible computers Issue text in ATX format is available for issues 16 to current CD ROM in MS DOS format also available containing most ACA related material Available from the Editor TO OBTAIN THESE MATERIALS Write to Or via Electronic Mail Dan Veeneman dan decode com PO Box 2442 Columbia Maryland 21045 2442 USA Allow 6 8 weeks for delivery No charge for hard copies but contributions to postage appreciated Disk charge 5 per disk specify format and density required ACA Issue Disks and additional crypto material resides on Decode the ACA Bulletin Board system 1 410 730 6734 available 24 hours a day 7 days a week 300 1200 2400 9600 14400 28800 baud 8 bits No Parity 1 stop bit All callers welcome SUBSCRIPTION Subscriptions are open to paid up members of the American Cryptogram Association at the rate of US 2 50 per issue Contact the Editor for non member rates Published three times a year or as submitted ma terial warrants Write to Dan Veeneman PO Box 2442 Columbia MD 21045 2442 USA Make checks payable to Dan Veeneman UK subscription requests may be sent to G4EGG CHECK YOUR SUBSCRIPTION EXPIRATION by looking at the Last Issue number on your address label You have paid for issues up to and including this number The Quagmires 1 and 2 G4EGG The Quagmire ciphers Practical Cryptanaly sis page 24 types 1 and 2 ar
25. Huachuca AZ Since then I have been self employed in various ways as an Internet consultant au thor trainer and speaker I like to say that I have been surfing the nets since 1960 See my home page at ei ther http www delphi com walthowe or http www tiac net users walthowe Oh yes My old NOM was WART HOG Anyone remember me I contributed some nasty cryptograms back then I hope to do so again ACA COMPUTER BULLETIN BOARD UPDATE All members of Krewe are welcome to use the ACA bulletin board system Decode for elec tronic mail to the Internet It is available 24 hours a day at 1 410 730 6734 Each user will automatically gain an Internet address of the form lt user gt decode com and may cor respond via e mail to members of the Krewe and other Internet users The system subscribes to a number of elec tronic mailing lists including Cypherpunks Microsoft s CryptoAPI project and Cloak and Dagger The FILES section also contains various ACA and cryptographic related files and programs as well as an assortment of other topics 26 Computer Supplement 21 Current PGP Versions Stale Schumacher PGP exists in several different versions If you are not sure which version is the right one for you you may find help here The following is a list of the most popular PGP versions avail able today PGP 2 3a This is the classic PGP version and until re cently this was the version generally u
26. OTO 690 IF SS gt 26 THEN SS SS 26 GOTO 700 MID RL RS SS 1 S PTL UCASE S CTL CHR 64 SS IF TYP 2 THEN SWAP PTL CTL GOSUB 400 NEXT NEXT NEXT IF CK 1 THEN CK 0 LOCATE 22 9 PRINT SPACE 30 GOTO 790 NEXT LOCATE 4 P 45 PRINT LOCATE 16 45 PRINT M RETURN gt start with notes on programme PRINT PRINT TAB 10 HD PRINT PRINT PRINT If input data is from a file the file name extension must be CT PRINT It is not necessary to enter the extension when giving file name PRINT PRINT Period may be from 4 to 9 PRINT PRINT Examination of both PT columns and alphabet grid should indicate more PRINT PT letters These are added by entering the PT col number or the grid 6 Computer Supplement 21 960 PRINT row number both are the same and then CT letter and PT letter 970 PRINT PRINT Entering 99 instead of a col will cross reference the known letters 980 PRINT This may be slow especially when there are a lot of letters in 990 PRINT PRINT Enter gt 99 to restart new crib position and 0 to end 1000 PRINT PRINT TAB 18 INPUT Quag 1 or Quag 2 TYP 1010 IF TYP lt gt 2 THEN TYP 1 1090 start here 1100 CLS PRINT PRINT TAB 10 HD PRINT 1110 INPUT Enter ciphertext ENTER for example F if data on disc CT 1120 IF CT THEN READ CT IF TYP 2 THEN READ CT ELSE READ TT 1125 PRINT CT
27. THE CRYPTOGRAM Spring 1996 FKK K K 2K K K K K K K K K K K K K 2K K OK K K OK COMPUTER SUPPLEMENT 21 2K K K K K K K K K K K K K K K K K 2K K K K K K In this issue THE QUAGMIRES 1 AND 2 G4EGG provides a program to aid in the solution of Quag mire ciphers ENIGMA 95 ESSAYONS and LANAKI introduce a QBASIC program to simulate an Engima machine with enhancements dBASE ADDITIONS Ken Mad gives some additions and shortcuts to PARROT s dBASE routines AN INTRODUCTION TO MODERN CRYPTOLOGY G H Foot has written an excel lent introduction to modern crypto issues A TRIP TO THE NSA MUSEUM BROADSWORD relates the details of a recent trip to NSA s public museum ENIGMA CONTEST DAEDALUS explains how he solved a publishing house contest CURRENT PGP VERSIONS A guide to the various versions and modifications of a popular cryptographic program BASIC PEEKS POKES AND SUBROUTINES If you re using BASIC this list may help you perform minor miracles Plus News and notes for computerists interested in cryptography and cryptographers in terested in computers Published in association with the American Cryptogram Association INTRODUCTORY MATERIAL The ACA and Your Computer 1p Background on the ACA for computerists As printed in ACA and You 1988 edition Also on Issue Disk 11 Using Your Home Computer 1p Ciphering at the ACA level with a computer As prin
28. allow diversions to discuss such topics Interestingly there is one and only one crypto system which is unbreakable This is the one time pad which combines and conceals the message to be transmitted with a series of numbers which are entirely random random means that it is entirely impossible to predict the next number from a knowledge of all pre vious numbers in the series But this cryp tosystem requires pads of random numbers to be prepared and to be available in advance to both the sender and receiver of a message 20 moreover there is the important limitation to general use that each pad can be used once and once only Nevertheless be prepared for new developments in this as in every other di rection About the Author Returning to the UK on retirement from the position of communications engineer with a US company I became interested in home computers as a hobby An extension of this hobby has been an inter est in modern cryptography and its applica Computer Supplement 21 tion as an aid to privacy in private and com mercial transactions via electronic media I have a joint UK Patent for an invention in this field and I am engaged with colleagues in the development of a secure cryptosystem which has a sound theoretical basis and also novel features My formal qualifications include Senior Mem ber of the IEEE in the US and Fellow of the TEE in the UK E Mail georgefoot oxted demon co uk W
29. bout the theory and the his tory of these machines I recommend a visit ZIMMERMANN CHARGES DROPPED Phil Zimmermann the author of the Pretty Good Privacy encryption program In 1991 the Federal government convened a Grand Jury and began and investigation into possible export violations for making PGP available online In January 1996 Phil posted the following message My lead defense lawyer Phil Dubois received a fax this morn ing from the Assistant US Attor ney in Northern District of Cali fornia William Keane The let ter informed us that I will not be prosecuted in connection with the posting to USENET in June 1991 of the encryption program Pretty Good Privacy The investigation is closed This brings to a close a criminal investigation that has spanned the last three years Id like to thank all the people who helped us in this case especially all the donors to my legal defense fund Apparently the money was well spent And Pd like to thank my very capable defense team Phil Dubois Ken Bass Eben Moglen Curt Karnow Tom Nolan and Bob Corn Revere Most of the time they spent on the case was pro bono I d also like to thank Joe Burton counsel for the co defendant There are many others I can thank but I don t have the pres ence of mind to list them all here at this moment The medium of email cannot express how I feel about this turn of events Spring 1996 23 ENIGMA The Random H
30. ched it could be worth somewhere in the 40K range It would be an interesting find After my friend showed the codebooks to Jack Jack showed us the NSA s newest ac quisition the BOMBE machine This ma chine was built by the Allies to speed up the cracking of Enigma coded messages Ap parently three Polish cryptanalysts were dis cussing over lunch how to speed up the decryp tion process and they came up with this ma chine When they went to name the machine they selected the name of their dessert bom bay ice cream or BOMBE Anyway this par ticular machine was in the Smithsonian and they agreed to give it to the NSA I don t know the terms of agreement The NSA still had to get some of the pieces from the Smith sonian so regrettably they did not have the whole machine there when I visited This was quite a large machine 5 000 lbs about 6 feet high 8 feet long and 2 feet wide It performed a brute force crack on the mes sages Some of the rotors it used spun so fast that they cracked on a regular basis this ma chine required a fair amount of maintenance After that I and my friends went around the rest of the exhibits They had Enigma machines field rotor sets T series Engimas that were sold to the commercial public be fore WWII an Enigma with a printer re covered from another U boat They also had the Tunny used by German high command the Purple Machine built by Friedman and his crew t
31. d who could I comfortably call at 6 30 a m The an swer to this double barreled question was obvi ous I telephoned the local Catholic church The job was now completed but for the trans mission of the result to the Random House WWW site Well it was a lot of fun and I learned never to overlook the obvious at least I think I did And for those who missed the solution QXQF VFLR TXLG VLWD PRUA nunc scio quid sita morx Latin nunc scio quid sit amor x English now I know what love is 24 Computer Supplement 21 WHAT THE OTHER GUY IS DOING LANAKI Randy Nichols asks One of the NCSAFORUM subscribers poised an interesting question about the Bell Book and Candle Cipher supposedly used during WWI and WWII I have searched my books and records and found Bell Bell Labs Book ciphers BBC and radio messages even found a movie with Jimmy Stewart and Tippy Hedron in it re garding a witch Followed that lead took the movie out looked for sorcery codes Then I pulled out the big guns called PHOENIX and MEROKE PHOENIX had a vague no tion but nothing came to mind Tam stumped Okay Krewe has anyone heard of this variant and if so when and where G4EGG Wilfred Higginson is using CRYPTODYCT with dBASE IV and some PRG Any interest from members of the Krewe to share dBASE routines and files RETREAD Penn Leary continues to pursue historical cryptographic matters in cluding ciphers in the works of
32. de the USA It is only available as source code and not yet as pre compiled binaries ViaCrypt PGP 2 7 1 ViaCrypt PGP is a commercial version of PGP available in the US and Canada only Phil Zimmermann says that no compromises in the cryptographic strength of PGP were made for ViaCrypt s version of PGP The ViaCrypt 27 PGP package includes program disks exe cutables only no source code a user manual and an individual user license The current release is available for MS DOS Macintosh and UNIX There is a special version avail able which interfaces to CompuServe s CIM Prices start at 100 for the DOS version To purchase ViaCrypt PGP or to find out more about it you can contact ViaCrypt 2104 W Peoria Avenue Phoenix AZ 85029 USA Phone 602 944 0773 Fax 602 943 2601 Credit card orders 800 536 2664 0800 1700 MST Mon Fri E mail lt info viacrypt com gt NSA Releases Crypto Documents The United States National Security Agency has declassified and sent to the National Archives more than 1 3 million pages of his toric material gleaned by US cryptographers The documents cover a stretch from before World War I to the end of World War II The collection will be available starting April 4 at the National Archives the federal agency that collects and catalogs official US documents Among the material being released are de tails of the Codetalkers Navajo Indians who used their native tribal la
33. e similar and mainly require the interchange of plaintext and cleartext alphabets in the solution method given in the above book The following pro gramme was developed as an aid in solving the type 1 but the few changes necessary to allow use with type 2 have been added The programme details are Lines 10 120 General set up and setting of constants Lines 900 1000 Notes on the use of the programme displayed on screen when run and selection of type i e 1 or 2 Lines 1100 1850 Get cleartext and crib from disk keyboard or example This is just my way of doing it and not necessarily the best Lines 1890 1990 Convert crib to pattern and drag through cleartext to find fits Note fit position s Lines 2100 2140 Prepare cleartext for printing on screen in columns of period width Lines 2200 2210 Select which fit to try If only one go straight into initial display and crib fitting plus other determined letters Lines 2250 2520 Initial display and crib fitting Note that the screen size limits amount of text that can be displayed The programme gives up to the first 18 lines of period widths of text so the last few lines may be omitted from the screen Lines 2600 2660 Select next action Do alphabet cross refer ences get more cleartext plaintext pairs or start again with new crib position Sub routines Lines 200 350 Change sections of text to patterns for cross checking Lines 400
34. e to the Krewe you are welcome to it although it weighs in at over 400 megabytes DAEDALUS David Hamer has moved again but this time only fourteen miles lat erally and a few hundred feet vertically He has added an aged 386DX to his collection of hardware which will be dedicated to perform ing those large calculations which would oth erwise occupy valuable time on his serious machine Richard Brisson hagelin magi com a student in LANAKTI s crypto class has some questions about a NEMA Machine and some about the ENIGMA Here are all the details I have on the NEMA don t think it was made by Hagelin unless the company below was a subsidiary of Hagelin The NEMA was made in 1947 by Aschmann amp Scheller A G Zurich it contains 10 rotors of which rightmost is coded red while all oth ers are black it was intended as a post war Enigma like commercial device and the man ual has both German and French instructions I would be most appreciative of any further de tails with regards to the NEMA such as actual purchasers users the Swiss and the com pany Spring 1996 Now on to the other topic of the ENIGMA My questions are the following e The main letter designator which we find on the German military Enigma s such as A most 3 rotors and M mostly Kriegsmarine are related to the types of users e The three letter code which precedes the serial number e g aye or jla which is o
35. eb Page http www cybervillage co uk personal gfoot NOTES TO AUTHORS The Computer Supplement is intended as a fo rum to publish articles on the cryptographic applications of computers We are always looking for submissions but we ask potential authors to bear in mind 1 Many readers are new to ciphers please include a brief description of the cipher in question 2 Many readers are new to computers ex plain why you are using a computer as well as how 3 Include the output of a typical run If possible build in an example for the reader to check the operation Indicate how long it took to obtain this result 4 Include a full description of how the pro gram works and back it up with com ments in the listing 5 Include a table of variables either sepa rately or as a part of the listing 6 If at all possible please submit every thing in electronic form either on a disk any IBM format uploaded to the ACA BBS or electronically mailed to dan decode com This makes it much easier for us to typeset 7 Send material for publication to Dan Veeneman PO Box 2442 Columbia Maryland 21045 2442 USA Spring 1996 21 A TRIP TO THE NSA MUSEUM BROADSWORD David W Cuccia Greetings everyone I want to share with you all some details about a recent visit I was lucky enough to make to the NSA Museum First The NSA Museum is located on Fort Meade in Maryland right next to the NSA headquarters
36. ere written to do it for both regular and reversing rotors The programs also produce a file on a floppy disk to simulate a set of rotors and print the re sults for record purposes Each rotor had to be unique from all others so use of random numbers was involved The plugboard was programmed so that it was possible to enter the 2 point from to sets that were to be connected Multiple sets could be created just as it is possible to have multi ple cable connections on a mechanical Enigma A file of plugboards is not needed because the variance within fixed fields is derived from the connections and to allow numbers of connec tions to be varied It was necessary though to provide for editing to insure that each position was used only once as in real life At this point the idea of expanding the Enigma came into being in the form of intro ducing variability between the keyboard and the plugboard such as the Uhr Box does It was decided to make the Enigma process the data in numerical form and expand it from a 26 to a 100 character format This numeri cal format 00 99 has the disadvantage of doubling the length of a message but it has certain advantages In addition to handling alphabetic letters it can also e Allow upper lower cases numbers sym bols punctuations and spaces to be en crypted e Better conceal the language and individ ual characters being transmitted e Eliminate the problem of a letter not
37. exported anyone may use it freely This version corrects a number of bugs found in PGP 2 6 and 2 6 1 If you are a US citizen liv ing in the US this is probably the PGP version you want MIT PGP 2 6 2 can be downloaded here PGP 2 6 3i This is the latest international version of PGP based on the source code for MIT PGP 2 6 2 and modified for international use PGP 2 6 3i is published by Stale Schumacher in Norway and differs from MIT PGP 2 6 2 in the follow ing ways e It does not use the RSAREF encryption library e It is 100 compatible with all other PGP 2 x versions e It corrects a number of bugs present in PGP 2 6 2 i e It compiles out of the box for many new platforms e It adds some new features without breaking compatibility with earlier ver sions PGP 2 6 31 is the most flexible up to date ver sion of PGP available today PGP 2 6 31 is probably illegal to use within the USA so if you are a US citizen you should use MIT PGP 2 6 2 or PGP 2 6 3 instead Spring 1996 PGP 2 6 3 If you compile the source code for PGP 2 6 3i using the DUSA option and linking with RSAREF rsaglue2 c instead of MPILIB rsagluel c you will get a version that identifies itself as PGP 2 6 3 It contains all the same bug fixes and improvements as PGP 2 6 31 but it will be slightly slower and the legal kludge cannot be disabled PGP 2 6 3 is not an official PGP version but is still per fectly legal to use insi
38. gma 95 and a program to pro duce pseudo random numbers to use in pro grams that produce the rotor disks Also in cluded are programs to analyze the Enigma 95 EPILOGUE The Enigma rotor operation principle has probably been long superseded by much more sophisticated methods of encryption that are faster and more secure but it will remain in teresting for a long time to amateurs such as myself It is something that is understand able and before the advent of the computer resulted in some beautiful machines The Enigma 95 is not one now but I believe that it could be translated into a handsome electro mechanical device It is something to dream about The only absolutely secure cipher is the One Time Pad and it has the disadvantage of re quiring copies to be destroyed after one use The Enigma 95 is an attempt to approach this holy Grail of cryptography by providing an al most unlimited supply of enhanced both in size and method of rotation Rotors Char acter Sets Superencipherment Tables and a lengthened Plugboard While I cannot prove it mathematically or otherwise I suspect that Spring 1996 the ability to use almost unlimited expend able sets of all possible combinations of these for very limited periods throw away feature such as is possible in the Enigma 95 would 13 strengthen any cipher considerably by pre venting the accumulation of sufficient material on which to base an in depth cryptanalysis
39. i CPEE 5 FJXEQGXX 8 omthe r 8 PEN O aeaiia dairi As State i eee ea 6 QKXLRFLB OS sds Ase 9 Pi RT Ee E E E E eae anne Sie gt Rear 7 AERUIUWU 10 o ar 10 Pt e a E EEEE EET sca EASE 8 FOXMFFWS 11 o t r 11 ABCDEFGHI JKLMNOPQRSTUVWXYZ XLJUSKXE 12 0 1 12 SOJHARVT Re arose t 13 QUXUTDZV 14 to 14 Col No FOCPOFMU 15 Ons 3 e3 15 TVVJXVTC LO ene f 16 FZVHUCDI 17 o istr ZUUFRSTX IKIRE EERE r 18 Now for the guess work or intelligent in tuition Line 1 of the alphabets shows h l and line 3 has f i It is reasonable to assume that these two will not marry as i j and or k must fit into one space h 1 So g must fill the f i gap To do this enter 3 for Col No e for clear text letter and g for plaintext letter Row 1 of cleartext block begins 1 h i Try light Col No 2 cleartext letter g plaintext letter i etc for cols 3 and 5 Then 99 in Col No to add this new information to all alphabets and plaintext grid Screen will then be as An aid to solving the QuagmireI and QuagmireII ciphers G4EGG RGEESEDI 1 light i 1 ZMYUXIZU 2 rT0 e 2 ct ABCDEFGHIJKLMNOPQRSTUVWXYZ XBRJSPLI 3 wie t ane 3 pt i OSA dae Naso ee Dies R E 1 XWYDSFWH 4 er t rm 4 pt 2 we Pe Mis E Bae e tr 2 4 DARDSTDG 5 ais tide 5 QYUFQUWW 6 t eart 6 PJFGQOBX 7 hmilesfr 7 F JXEQGXX 8 omthe r 8 QKXLRFLB Of Gs 2 tea 9 AERUIUWU 10 f o are 10 FOXMFFWS 11 o t r 11 XLJUSKXE 12 0ot i 12 SOJHARVT 13
40. int Screen PRTSC routine address Following are some BASIC statements and subroutines showing how to use the above in formation plus additional functions KEYBOARD e To disable entire keyboard DEF SEG 64 OUT 97 204 e To re enable keyboard DEF SEG 64 OUT 97 76 e Clear line buffer DEF SEG POKE 106 0 e Clear Keyboard Buffer DEF SEG 0 POKE 1050 PEEK 1052 e Turn on NUM LOCK DEG SEG amp H40 POKE amp H17 PEEK amp H17 OR 32 e Turn off NUM LOCK DEG SEG amp H40 POKE amp H17 PEEK amp H17 AND 223 e Turn on CAPS LOCK DEG SEG amp H40 POKE amp H17 PEEK amp H17 OR 64 e Turn on CAPS LOCK DEG SEG amp H40 POKE amp H17 PEEK amp H17 AND 171 30 Computer Supplement 21 Restore Function Keys to Default values 10 DEF SEG amp HFACE 20 K 1 30 I 13 40 T STRING 13 32 J 1 50 T1 PEEK I IF T1 lt O THEN MID T J 1 CHR T1 J J 1 I I 1 GOTO 50 60 KEY K LEFT T J 1 IF K lt 10 THEN K K 1 IT I 1 GOTO 40 ELSE KEY ON Disable and re enable CTRL BREAK 100 Subroutine to save old CTRL BREAK address and set new to IRET 110 DIM OLD 4 120 DEF SEG 0 130 FOR I amp H6C TO amp H6F 140 OLD I amp H6C PEEK I The array OLD must remain available 150 NEXT 160 establish new CTRL BREAK address point to IRET 170 POKE amp H6C amp H53 180 POKE amp H6D amp HFF 190 POKE amp H6E amp HO 200 POKE amp H6F amp HFO 210 DEF SEG RETURN
41. iring of the rotors was fixed It never changed except for a few specialized purposes While the math ematical possibilities were astronomical only a small portion of them were uti lized probably because of manufactur ing cost and logistics considerations 2 There were only eight rotors in a set and only 3 or 4 could be used at a time 3 The rotors rotated only very restricted basis One moved one position each time The second moved only after the first had moved 1 to 26 positions The 3rd moved only after the 2nd had moved 1 to 26 positions There were notches on the rotors to accomplish this and the ro tors could be set so that the movements occurred at different times but move ment of two rotors was infrequent and movement of all rotors was limited and somewhat predictable 4 The reversing reflecting rotor did not move nor could it be moved except on the earlier models Spring 1996 5 A subtle weakness was that a given let ter could never be encrypted as itself 6 It was expensive and labor intensive both to manufacture and to operate Once it had been determined how to simulate the rotation of rotors and to simulate the transfer of the electrical current between rotors correctly a ma jor problem was solved Then it was necessary to determine how to keep the internal wiring connections unchanged during rotation This was followed by developing a method of selecting and in stalling the rotors at a give
42. is employed to establish initial contact between the parties but subsequently the main body of the message is transmitted with a second cryptosystem which functions more rapidly because it requires less comput ing effort A prominent example of a hybrid cryptosys tem is PGP standing for Pretty Good Pri vacy which is a combination of RSA with IDEA a cryptosystem of Swiss origin PGP was introduced in the USA by Mr Philip Zimmermann and soon gained recognition throughout the world To understand the background to this development it is neces sary to provide an explanation of the discus sions and controversies which relate to cryp tography at the present time Until recently the practice and preserve of cryptography was largely the prerogative of governments each desiring to conduct their political and military communications in pri vate whilst learning as much as possible of the affairs and intentions of other governments For the proper regulation of domestic matters Spring 1996 each government prohibited the transmission of messages in codes and ciphers of any type which an agency of the government could not decrypt Into this well ordered world burst a flood of electronic communications passing over world wide electronic networks which had little re spect for national frontiers but which con veyed a vast amount of private commer cial banking financial and other traffic which required privacy for competing bu
43. it cycles around to position 1 when position 6 or 7 is used A SuperEnciphering Table Figure 18 accomplishes this and there is a matching Su perDeciphering Table Figure 19 to reverse it Text input requires no use of the ENTER key and the computer buffer handles rapid input so that the entry of clear or cipher text is faster than that of the original Enigma Input is displayed on the monitor and the resulting cipher clear text is displayed immediately be low so that it is possible to visually check it If an error occurs a simple procedure allows you to correct it without having to re type ev erything A screenful of data consists of 6 sets of double lines one input one output dou ble spaced with the sets separated by a dotted line for clarity There are 27 inputs per line for a total of 162 When the 159th 161st are entered a beep sounds to alert you to the ap proaching end of a screen This allows you to make a final check of the input for errors and easily correct them before entering the 162nd which triggers printing that screenful to pa per During the printing you can start enter ing the next screenful A limit of 1943 inputs 12 screenfuls less 1 was arbitrarily chosen for demonstration purposes more would be pos sible depending on memory available This limit can be easily set to a shorter value to Spring 1996 control message length to make cryptanalysis more difficult Printing is considered essentia
44. l for the purpose of having a record of what was sent and how it was encrypted or decrypted e g was the cleartext entered correctly and was the ma chine correctly set It also eliminates the need for a second person to transcribe the output Following are four exhibits that are examples of the printouts that can be produced A Encryption into numeric form B Decryption of Exhibit A C Encryption in Superenciphered Form D Decryption of Exhibit C Each exhibit is divided into the following parts The Heading This indicates whether it is encryption or de cryption and the date and time that the set tings were entered This does not change for repeated use of the settings for two or more consecutive messages To enter a new date time group or change the inter nal settings the program must be completely restarted See Al B1 C1 or D1 The Internal Control Settings This indicates the number of plugboard con nections used the specific plugboard connec tions the number of rotors used the spe cific rotor numbers in the position sequence and then each rotors orientation frontwards or backwards The reversing rotor number is indicated Next the unique rotation value for each rotor and the reversing rotor are shown followed by the character set number and its rotation value These constitute the internal settings that would be specified by the Sig nal Operating Instructions SOI All of these settings generate an Inte
45. less the parties concerned had the opportunity to meet and pass Keys directly from one to another the secure con veyance of Keys between them has always been and remains a serious problem In circumstances in which the highest possi ble security is required a courier is employed for the transmission of the Keys but this is a slow and expensive process In any case no method is completely proof against malicious ingenuity bad faith corruption and like mea sures which it must be anticipated an enemy will employ energetically An important development occurred in the 1970 s when it was shown that different Keys could be employed for encryption and decryp tion Moreover one of the Keys could be pub lished without prejudicing security if the other Key were kept secret The Key which could be published was called the Public Key and the system became known as Public Key Cryptog raphy The secret Key is known as the Private Key With Public Key Cryptography it is pos sible to utilise a Public Key for secure commu nication with the owner of that Key without the need for any prior contact Only the per son in possession of the Private Key is able to decrypt the ciphertext and to recover the message Moreover if double encryption is performed it becomes possible to establish that the com munication came from a particular person and from nobody else both the origin of the message and its content can be authenticated
46. mory installed Only works for greater than 48k DEF SEG 0 MEMORY PEEK amp H413 256 PEEK amp H414 or put another way DEF SEG 0 PEEK 1040 and 12 4 4 Memory on Mother board PEEK 1045 256 PEEK 1046 Expansion memory add on PEEK 1043 256 PEEK 1044 Total memory GAME ADAPTER Determine if game adapter exists DEF SEG 0 GAME ADAPTER PEEK amp H411 AND amp H10 IF GAME ADAPTER O THEN GAME ADAPTER No ELSE GAME ADAPTER Yes Installed MISCELLANEOUS To unprotect a BASIC program that was saved with P First you must create a file to overlay the P setting From the DOS prompt start up BASICA or BASIC and enter the BA SIC command BSAVE UN P 1124 1 This will create a file on your default drive named UN P Next LOAD your program that had been saved using P If it was named MYPROG BAS the BASIC command would be LOAD MYPROG Now to use the UN P file to overlay the protection setting use the command BLOAD UN P 1124 You may now use the LIST EDIT and SAVE commands as usual INTERRUPTS Following is a program by Richard Tremmel to print all the BASIC interrupts It is set to write the interrupt locations to a printer 100 REM INT LIST IBM PC Software Interrupt Listing by Richard L Tremmel 110 DEF SEG 0 120 DIM NAM 255 130 DEF FNJUSTIFY STRG LNGTH RIGHT 0000 STRG LNGTH 140 TITLE INT ADDR VECTOR FUNCTION 142 REM 144 FOR I O TO
47. n author editor in the field of Classical Cryptography Mr Nichols is the author of Classical Cryptography a book to be published in 1997 When not glued to the computer screen think ing up ways to torture his students Mr Nichols has another life as a senior manager Computer Supplement 21 with a Fortune 100 Company in charge of implementing a massive ISO 9000 standards project for his company He has previously served as Manager of Raw Materials Inven tory Marine Operations Transportation and Computer Applications Departments Mr Nichols has 30 years foreign and domestic project management experience in a wide vari ety of leadership roles in the engineering con struction and chemicals industries Mr Nichols holds a BSCHE degree from Tu lane University New Orleans LA 1967 a MBA from University of Houston Houston TX 1970 and a MSCHE from Texas A amp M University Kingsville TX 1991 In 1995 Randy was awarded a 2nd Degree Black Belt in Tae Kwon Do Korean Karate by the Moo Duk Kwan International and the American Korean Tae Kwon Do Associ ations He teaches Tae Kwon Do Self Defense and Rape Defense courses in Corpus Christi Texas 5953 Long Creek Drive Corpus Christi Texas 78414 USA ACA CD ROM Available There is now a CD ROM containing ACA and crypto related materials available from the Editor Through the wonders of Recordable CD ROM the following items are available in MS DOS format
48. n be skipped and was pro vided only to assist any system analysis See A4 and C3 This completes the printing Next displayed on the monitor is an option to re use the Internal Control Settings for another message it was assumed that these would remain in effect for a period of time as was the case for the Enigma If this is not selected the program ends COMPUTING REQUIREMENTS The Enigma 95 is a program written in Mi crosoft QBasic This was done so that it could be run on any standard MS DOS computer us ing MS DOS 5 or higher QBasic is bundled with MS DOS thereby eliminating the need for a specialized computer It fits onto a 3 5 inch floppy disk together with the necessary data files that constitute the Regular Rotors Set Reversing Rotors Set Computer Supplement 21 Character Sets and Superencipherment Ta bles It is possible to also have on the same disk the programs that create these files and the necessary documentation DOC text files for each one This makes the Enigma 95 very portable very inexpensive and very easy to replicate Any computer that will run MS DOS QBasic is suitable for the Enigma 95 A color monitor is preferred but not essential A printer is very useful but could be eliminated if one is will ing to copy output manually from the monitor screen as the original Enigma required There is provided a program that produces a graphic representation of the circuit path through the Eni
49. n mine represents the manufacturer e Sources for the bulbs which have to be 12mm screw type hemispherical and 3 5 volts WARTHOG Walt Howe writes Now that I ve established contact I guess I should re introduce myself I joined the ACA in 1960 or 1961 while I was attending the Army s old 21 week MOS 981 Cryptana lytic Specialist Course at Fort Devens at the US Army Security Agency Training Center amp School I was a frequent completer during the 60 s and since I stayed on as an Cryptana lytic Instructor at Ft Devens first in uni form and then as a Civil Servant I steered many military members to the ACA partic ularly those who loved the challenges of the theory and the solutions Somewhere through the years I dropped my ACA subscription 25 I remained as a Signals Intelligence trainer training developer and training manager at the USASATC amp S later renamed as the US Army Intelligence School Fort Devens Along the way the 981 was renamed as the 98B MOS and then folded into the 98C Traffic Analyst MOS I was delighted to have the chance to write the Army s Field Manual FM 34 40 2 Basic Cryptanalysis published in 1990 The man ual as all Army manuals acknowledges no au thorship but you can find my name in there anyway concealed in Chapter 14 if you hap pen to have a copy I retired from Civil Service in 1992 as the School began transferring to merge with the Intelligence School at Fort
50. n position and then how to rotate them to an initial set ting Having an old Model D Enigma 3 rotor so that it was possible to deter mine what the outcome should be was helpful Creation of rotors presented a challenge in es tablishing the internal wiring and in making a set from which to choose three Edward H Hebern used the Interval Method of wiring his rotors so it was decided to use that ap proach For those who are not familiar with it it involves determining the positional dif ference interval between points connected on opposite faces of the rotor For a 26 A Z position rotor the intervals range from 0 to 25 with each interval being used only once But the geometry of the problem prevents one interval from being used and requires one in terval to be used twice All intervals are mea sured in the same direction For example a connection from point A on one face to point C on the other has an interval of 2 assuming opposite positions are identified with the same letter I don t know how Mr Hebern did it but it is a job perfectly suited for a computer At any rate wiring a rotor using the Interval Method can be very tedious because it involves a lot of trial and error if done manually or as it turned out by computer It would be in teresting to know if there is a simple algorithm that would produce a more secure encryption After trying to do it manually by diagram ming on paper programs w
51. ndows 3 1 Write Has a matching DOC file The 1st DOC and FLO files are DOS files The BAS and DAT files are QBASIC or QUICKBASIC files The WRI file is a WINDOWS 3 1 Write file AUTHOR BIOGRAPHIES Clarence E Tyner Jr 69 is retired from the Army as a Major in the Corps of Engi neers in which he served in topographical and engineer technical intelligence services He is also a retired Certified Public Accountant having specialized in Internal Auditing for a large county wide public school system His interest in cryptography began in World War II with the M 209 and is a collector of both machines materials and publications that are about cryptography 14 11322 Carrollwood Drive Tampa Florida 33618 USA Randall K Nichols 52 has served as the President 1994 1996 and Vice President 1992 1994 of the American Cryptogram As sociation ACA which since its formation in 1929 has been devoted to the pursuit of pri marily classical and recreational cryptography Mr Nichols is the Aristocrats Department Editor for ACA s bimonthly publication The Cryptogram Mr Nichols also works as Cryp tology Section Leader for the National Com puter Security Association NCSA Com puserve Forum Mr Nichols is currently teaching one of the first electronic courses in classical cryptography on the Internet One hundred forty nine 149 students are partici pating worldwide He is considered an expert as well as a
52. nguage to confuse US wartime enemies while communicating to US forces For those with World Wide Web access a list of the documents is available on the NSA web page under Project OPENDOOR The Uniform Resource Locator URL is http www nsa gov 8080 For those without Web access S LOST Fred Kolbrener has uploaded a copy of the listing of the documents on file at the National Archives which NSA declas sified The file is called NARA NSA ZIP and is located in the in the directory crypto general crypt info in the Crypto Drop Box sage und nodak edu The file size is about 125Kb and the contents of the ZIP file expand to more than 400 kilobytes of ASCII listings 28 Computer Supplement 21 Basic Peeks Pokes and Subroutines Mike Todd This list of memory addresses contains infor mation about the status of the PC and or lo cations which may be modified to change the way the PC reacts to its world The programs to use this information have been compiled by a large number of people Some of it may be gleaned from the IBM Technical Reference Manual and the BASIC manual Some of it ex ists only because someone worked very hard to find a way to make something happen Some of it exists because someone made a mistake and was presented with a new capability be cause of it No matter who found it or how the information was found this document provides some really useful information for BASIC pro grammers It even provides g
53. nt before the message can be understood Machines for cryptographic purposes came into prominence during the Great Wars of this century for the protection of military and po litical intelligence The story of their successes and sometimes of their failures because of brilliant counter intelligence operations has been related extensively More recently all other methods have been eclipsed by the introduction of modern com puters which can manipulate numbers rep resenting characters of a size and complex ity far beyond anything which could be han dled manually But computers have also been enlisted for the assistance of Cryptoanalysts those people who exercise ingenuity and cun ning to unravel the secrets of cryptography without the assistance or the knowledge of the Cryptographers so that the battle of wits and skills between the opposing crafts continues more intensively than ever with the rapid growth of computing power being pressed into the service of each of the rival factions as one tries to outperform the other Entering the fray also are the Mathematicians because the secrets of encryption are nowa days based on transformations in number the ory of a most advanced mathematical nature advances which have become feasible only because of the enormously increased comput ing power which is available Any cryptosystem which has been validated for extensive use will have been subjected pre viously to in
54. number or the grid row number both are the same and then CT letter and PT letter Entering 99 instead of a col will cross reference the known letters This may be slow especially when there are a lot of letters in Enter gt 99 to restart new crib position and 0 to end Quag 1 or Quag 2 Enter 1 Input of cleartext crib and period are then requested RETURN key lets programme supply the required data Screen then shows An aid to solving the QuagmireI and QuagmireII ciphers G4EGG Enter ciphertext ENTER for example F if data on disc RGEESEDIZMYUXIZUXBRJSPLIXWYDSFWHDARDSTDGQYUFQUWWP JF GQOBXF JXEQGXXQKXLRFLBAERUIUW FOXMFFWSXLJUSKXESO JHARVTQUXUTDZVFOCPOFMUTVV JXVTCFZVHUCDIZUUFRSTX Enter crib EARTHMILESFROMTHE And period 8 Spring 1996 The periods are run to show that something is going on crib dragging is not very fast In this case only one position matches so the programme goes straight into the next stage the display of cleartext the plaintext grid and the alphabets An aid to solving the QuagmireI and QuagmireII ciphers G4EGG RGEESEDI 11 h i 1 ZMYUXIZU 2 T0 2 ct ABCDEFGHIJKLMNOPQRSTUVWXYZ XBRJSPLI Be wai tke toon 3 pt 1 OUMoaen es Riedl neat Rogie 1 XWYDSFWH 4 r r 4 Pt 2 gees Ts of Sais eee aes Sens 2 DARDSTDG Bt ig ale es i 5 Pts 8 E a onc ae eats tr 3 QYUFQUWW 6 eart 6 pt 4 gee Le cee ee Ong os ao 4 PJFGQOBX 7 hmilesfr 7 pE 5r mahao eaa een
55. o crack the Japanese purple code part of a purple machine recovered from the Japanese embassy in Berlin a Jade machine a Hagelin Machine a Russian coding machine some Venona documents a rare book collec tion started by Friedman which contained one book from the 16th century a 300 ter 22 abyte tape drive about the size of a walk in closet complete with a robot arm to retrieve tapes one of the first Cray machines used by the NSA they made it into a bench which you can sit on and relax several models of secure phones FAX machines and some of the more recently used field coding machines After taking a few pictures I returned to the conference room where my two friends were measuring rotors from two rotor sets I helped buzz out a reflector rotor The friend who has all the mappings is away on a business trip and when he returns he will find me gone on a vacation trip When I touch base with him Computer Supplement 21 again I will get the mappings and post them for your enjoyment We also used an Enigma machine which is on display for the public to use Its really some thing to actually use the very machine that was regarded as the top secret device of the German command only 50 short years ago Very impressive Overall I was very impressed with the mu seum it has a very nice collection that is well kept and well presented The curator and the other staff were all very helpful and very knowledgeable a
56. ood information for other programmers who will access the PC memory directly BIOS LOCATIONS By specifying a DEF SEG amp H40 in any BASIC program it is possible to reference the follow ing vectors fields in the ROM BIOS area by using a PEEK function and the following off sets from the current segment as defined by the DEF SEG statement e Offset amp HO RS232 Addresses on your IBM PC This will allow you to tell how many up to four async cards are attached if any e amp H8 Printer Addresses on your IBM PC This will tell you what printer addresses and how many up to four exist Each is addressed by a two byte Hex value e amp H10 Equipment Flag This field describes the setting of the options switches It describes what optional devices are at tached to the system The following lists the bit significance of this field Bit 0 Indicates that there are diskette drives on the system 0 No diskettes 1 1 or more diskettes Bit 1 8087 0 Not installed 1 Installed Bit 2 3 Planar RAM Size PC 1 XT and PC 2 00 16K 64K 10 32K 128K 01 48K 192K 11 64K 256K Bit 4 5 Initial Video Mode 00 Unused 10 40x25 Color 01 80x25 Color 11 80x25 Mono or both Bit 6 7 Number of Diskette Drives bit 0 1 in all cases 00 1 10 2 01 3 11 4 Bit 8 Unused Bit 9 10 11 Number of RS232 Cards attached Bit 12 Game I O Attached Bit 1
57. ouse Contests David Hamer DAEDALUS Early in October 1995 Random House pub lished ENIGMA a novel by Robert Harris based upon a series of actual events which took place in and around Bletchley Park and Cam bridge University in the early days of World War Two As a promotion the publisher of fered a complimentary copy of the book to the first fifty or so solvers of a very simple substi tution cipher presented on the Random House pages of the World Wide Web This first cipher a Patristocrat was easily de crypted by a number of ACA members who in very short order received copies of the book together with an indication that Random House would shortly announce a more difficult cryptographic challenge this time with cash prizes Later in October the new challenge appeared on the Random House World Wide Web site The cut off date for entries was to have been December 15 1995 but this date was extended to January 3 1996 Thirteen prizes were awarded four of these going to ACA mem bers alphabetically Frank Dezzi SIM RAM Jim Gillogly SCRYER David Hamer DAEDALUS and Bill Sutton PHOENIX The text of the cipher QXQF VFLR TXLG VLWD PRUA Too short for statis tics so it could be anything My personal story begins on the day I received the free copy of ENIGMA well before the second contest was announced The above ci phertext appeared as part of the author s dedi cation at the beginning of the book Out
58. ps supplied by the US Government each chip containing 19 a unique code which is identifiable Using this code and with the sanction of a US court or der the US Government could recover any Key from compulsory escrow with an approved US government agency to allow the appropri ate US government agency surreptitiously to decrypt all messages being transmitted with the chip under supervision Fierce objections to the plan have arisen Other countries have attempted to impose a complete ban on cryptography other than for their own government communications This is unlikely to be practical some forms of cryptography are essential for banking and similar purposes and are already in extensive use The arrival of the Internet and its employ ment for an enormous and still rapidly growing number of diverse purposes is another reason why cryptography is required to safeguard the privacy of communications transmitted elec tronically But this is a contentious and dif ficult area in which to introduce any agreed measures of control as it is predominately in ternational in character It has not been specifically indicated that mes sages in the context of this article includes data graphics sound and any and every kind of information which can be transmitted from place to place Moreover it includes such tech niques as steganography for example hiding dramatic text within a picture of an innocuous scene but space does not
59. rnal Checksum which is used to verify that the settings have been correctly entered This checksum is printed If it does not agree with that provided in the SOI then all the settings must be re entered by restarting the 11 program Intermittent rotation of each rotor is a function of the installed rotors and previ ous entries and does not have to be specified The External Control Settings This lists the settings that the operator selects and enters for the specific message They con sist of the Initial Settings of each rotor and op tionally the Superencipherment Table number if it is used These settings add to the Internal Checksum and produce an External Checksum in the form of a 2 digit number mod 100 of the total sum that is sent with the message The superencipherment table counter setting is NOT included and is NOT sent because the recipient does not have to know it See Al B1 Cl D1 The Input Output Message Text This duplicates that which appears on the monitor screen and is provided primarily for a message audit to insure that the message was entered correctly Each line has 27 in puts with the 27 outputs below Twenty seven was used to provide legibility on an 80 column screen Six such lines are possible for each screenful See Al B1 C1 or D1 The Message Control Data A count of the input characters message length is provided for both superenciphered and non superenciphered messages
60. sed by PGP users all over the world You may still use PGP 2 3a if you want to but you may experience problems when trying to process messages and keys generated with PGP 2 6 and later versions or when using keys that are larger than 1280 bits the maximum size is now 2048 bits PGP 2 3a is presumably il legal to use within the USA because of patent restrictions PGP 2 6ui This is an unofficial hacked version of PGP 2 3a which aimed at correcting the incompat ibility problems introduced by MIT PGP 2 6 Please observe that PGP 2 6ui is not a true 2 6 version as it is based on the source code for PGP 2 3a and as such does not include the improvements and bug fixes found in the newer versions PGP 2 6ui was published by mathew in the UK but is no longer supported PGP 2 62ui Tony Lezard in the UK based this version of PGP on mathew s 2 6ui but tried to bring it up to date with the latest PGP 2 6x improve ments bigger keys bug fixes new command options etc MIT PGP 2 6 2 This is the latest official version of PGP re leased by MIT and adapted some would say mangled for use in the USA 1 It creates messages that cannot be read by PGP versions prior to 2 5 2 It uses the RSAREF encryption library making it slightly slower on most plat forms Furthermore it does not under stand the old signature format used by PGP 2 2 and earlier versions PGP 2 6 2 is illegal to export from USA but once
61. siness in terests which needed protection from fraud and financial loss and which demanded non interefernce from government A new situation arises inasmuch as modern computers commonly employed in home and office have become so powerful that they have the potential to make use of strong cryptosys tems which are difficult or virtually impossi ble for government agencies to break Gov ernments are loath to yield their overriding power to read every communication transmit ted by electronic means They declare that their right to do so is necessary for the de tection of criminals and terrorists and for the suppression of unsocial practices The debate continues and is especially intense in the USA where cryptosystems can be classified as mu nitions the export of which is banned In this contentious atmosphere Philip Zim mermann introduced his PGP a cryptosys tem providing high grade security In some manner knowledge of PGP passed out of the USA an illustration of the impossibility of confining any system within national frontiers in modern times and Zimmermann was in peril of being charged with exporting muni tions That threat is now lifted but nothing else is resolved In the meantime the US government has pro posed a plan for escrow cryptography known as Clipper The idea is that the US govern ment would permit the use of a secure high grade cryptosystem designed by the US gov ernment if it were confined in chi
62. ted in ACA and You 1988 edition Frequently Asked Questions approx 20p with answers from the Usenet newsgroup sci crypt REFERENCE MATERIAL BASICBUGS Bugs and errors in GW BASIC 1p Also on Issue Disk 11 BBSFILES List of filenames and descriptions of cryptographic files available on the ACA BBS files also available on disk via mail BIBLIOG A bibliography of computer magazine articles and books dealing with cryptography Updated August 89 available on Issue Disk 11 CRYPTOSUB Complete listing of Cryptographic Substitution Program as published by PHOENIX in sections in The Cryptogram 1983 1985 With updates from CS 2 3 available on Issue Disk 3 DISKEX A list of programs and reference data available on disk in various formats Apple Atari TRS80 Commodore IBM Mac Revised March 1990 ERRATA sheet and program index for Caxton Foster s Cryptanalysis for Microcomputers 3p Reprint from CS 5 6 7 and 9 disk available from TATTERS with revised programs BACK ISSUES 2 50 per copy All back issues from 1 to 20 are available from the Editor ISSUE DISKS AND CD ROM 5 per disk specify issue s format and density required All issues presently fit on two IBM High Density 3 5 inch 1 44M floppy disks archived with PKZIP For other disk formats ask Disks contain programs and data discussed in the issue Programs are generally B
63. tensive examination for potential weaknesses by experts in this field It is al ways a requirement that it must be possible to publish full details of the nature of the crypto system and the method in which it operates without diminishing the security it provides The cryptosystem must be secure against all attacks in circumstances in which the Key is unknown It has also to be assumed in assessing the merit of a cryptosystem that an eavesdropper is able to intercept encrypted messages during trans mission that he is able to obtain specimens of the plaintext which is a message before en cryption and compare it with the ciphertext which is the message after encryption that he can generate plaintext and ciphertext with Keys he may choose in his attempts at cryp toanalysis and that he has as much time as he wishes for this purpose Frequent changes of the Key provide much ad ditional security Nevertheless it is never pos sible to prove beyond doubt that a cryptosys tem is totally secure or to be absolutely certain that a weakness in a cryptosystem does not exist so that a short cut to decryption with out knowledge of the Key can be discovered There is one exception the so called One Time Pad which will be described later but which unfortunately is cumbersome and has limited application in practice 18 Historically and until very recent times the same Key was required for encryption and de cryption so that un

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