103:
1119:
51:(1312–1359), contained the first published discussion of the substitution and transposition of ciphers, as well as the first description of a polyalphabetic cipher, in which each plaintext letter is assigned more than one substitute. However, it has been claimed that polyalphabetic ciphers may have been developed by the Arab cryptologist
110:
Trithemius's idea was to encipher the first letter of the message using the first shifted alphabet, so A became B, B became C, etc. The second letter of the message was enciphered using the second shifted alphabet, etc. Alberti's cipher disk implemented the same scheme. It had two alphabets, one on a
66:
around 1467 was an early polyalphabetic cipher. Alberti used a mixed alphabet to encrypt a message, but whenever he wanted to, he would switch to a different alphabet, indicating that he had done so by including an uppercase letter or a number in the cryptogram. For this encipherment
Alberti used a
118:
in both cases was poorly concealed from attackers. Even
Alberti's implementation of his polyalphabetic cipher was rather easy to break (the capitalized letter is a major clue to the cryptanalyst). For most of the next several hundred years, the significance of using multiple substitution alphabets
111:
fixed outer ring, and the other on the rotating disk. A letter is enciphered by looking for that letter on the outer ring, and encoding it as the letter underneath it on the disk. The disk started with A underneath B, and the user rotated the disk by one letter after encrypting each letter.
119:
was missed by almost everyone. Polyalphabetic substitution cipher designers seem to have concentrated on obscuring the choice of a few such alphabets (repeating as needed), not on the increased security possible by using many and never repeating any.
1099:
929:
356:
126:
had been developed. A reasonable implementation would have been (and, when finally achieved, was) vastly harder to break. It was not until the mid-19th century (in
782:
122:
The principle (particularly
Alberti's unlimited additional substitution alphabets) was a major advance—the most significant in the several hundred years since
91:. Unlike Alberti's cipher, which switched alphabets at random intervals, Trithemius switched alphabets for each letter of the message. He started with a
99:, used 24 letters). Each alphabet was shifted one letter to the left from the one above it, and started again with A after reaching Z (see table).
232:
276:
349:
775:
301:
181:
342:
978:
768:
1094:
1049:
862:
1147:
973:
1089:
1079:
1069:
924:
173:
1074:
1064:
867:
827:
820:
810:
805:
31:
is probably the best-known example of a polyalphabetic cipher, though it is a simplified special case. The
815:
321:
285:
1122:
968:
914:
693:
248:
63:
618:
1084:
1008:
724:
628:
582:
572:
567:
562:
554:
847:
743:
738:
652:
486:
254:
146:
76:
24:
953:
937:
884:
719:
638:
544:
476:
123:
407:
316:
28:
114:
The cipher was trivial to break, and
Alberti's machine implementation not much more difficult.
102:
1013:
1003:
874:
688:
608:
577:
471:
402:
297:
272:
177:
135:
88:
167:
948:
365:
509:
466:
435:
417:
198:
127:
48:
1023:
943:
904:
852:
837:
728:
623:
504:
397:
392:
265:
59:
44:
32:
1141:
1104:
1059:
1018:
998:
894:
857:
832:
680:
534:
514:
494:
445:
425:
139:
1054:
899:
889:
879:
842:
791:
613:
524:
430:
92:
83:(Six books of polygraphia), which was published in 1518 after his death—invented a
290:
35:
is more complex but is still fundamentally a polyalphabetic substitution cipher.
1033:
698:
665:
660:
529:
131:
69:
993:
963:
958:
919:
732:
714:
519:
450:
983:
670:
1028:
988:
440:
52:
73:, which implemented a polyalphabetic substitution with mixed alphabets.
909:
633:
499:
373:
603:
598:
539:
138:'s generally equivalent public disclosure some years later), that
101:
96:
95:, a square with 26 letters in it (although Trithemius, writing in
231:(square table of transpositions, or "Vigenère table") appears on
142:
of well-implemented polyalphabetic ciphers got anywhere at all.
764:
338:
267:
Codes and
Ciphers: Julius Caesar, the Enigma and the Internet
223:… (Basel, Switzerland: Michael Furter and Adam Petri, 1518),
253:
A Treatise on
Ciphers, trans. A. Zaccagnini. Foreword by
930:
Cryptographically secure pseudorandom number generator
326:
1042:
798:
707:
679:
651:
591:
553:
485:
459:
416:
383:
372:
289:
264:
169:Passwords: Philology, Security, Authentication
776:
350:
27:, using multiple substitution alphabets. The
8:
16:Multiple-substitution writing system cipher
783:
769:
761:
380:
357:
343:
335:
331:
327:
47:(1355–1418), based on the earlier work of
271:, Cambridge: Cambridge University Press,
158:
7:
197:Maclean, Donald (20 February 2012),
14:
227:(fifth book), pages 461-462; the
87:polyalphabetic cipher called the
1118:
1117:
979:Information-theoretic security
1:
55:(801–873) centuries earlier.
263:Churchhouse, Robert (2002),
229:Recta transpositionis tabula
1095:Message authentication code
1050:Cryptographic hash function
863:Cryptographic hash function
1164:
974:Harvest now, decrypt later
130:'s secret work during the
1113:
1090:Post-quantum cryptography
760:
334:
330:
1080:Quantum key distribution
1070:Authenticated encryption
925:Random number generation
174:Harvard University Press
1075:Public-key cryptography
1065:Symmetric-key algorithm
868:Key derivation function
828:Cryptographic primitive
821:Authentication protocol
811:Outline of cryptography
806:History of cryptography
816:Cryptographic protocol
366:Classical cryptography
322:Topics in cryptography
249:Alberti, Leon Battista
221:Polygraphiae libri sex
166:Lennon, Brian (2018).
107:
81:Polygraphiae libri sex
969:End-to-end encryption
915:Cryptojacking malware
105:
64:Leon Battista Alberti
21:polyalphabetic cipher
1085:Quantum cryptography
1009:Trusted timestamping
725:Index of coincidence
629:Reservehandverfahren
286:Gaines, Helen Fouché
258:, Torino: Galimberti
67:decoder device, his
848:Cryptographic nonce
744:Kasiski examination
739:Information leakage
147:Kasiski examination
77:Johannes Trithemius
954:Subliminal channel
938:Pseudorandom noise
885:Key (cryptography)
720:Frequency analysis
619:RasterschlĂĽssel 44
124:frequency analysis
108:
1148:Classical ciphers
1135:
1134:
1131:
1130:
1014:Key-based routing
1004:Trapdoor function
875:Digital signature
756:
755:
752:
751:
647:
646:
278:978-0-521-00890-7
219:Johann Tritheim,
136:Friedrich Kasiski
89:Trithemius cipher
1155:
1121:
1120:
949:Insecure channel
785:
778:
771:
762:
381:
359:
352:
345:
336:
332:
328:
306:
295:
281:
270:
259:
235:
217:
211:
210:
209:
207:
194:
188:
187:
163:
1163:
1162:
1158:
1157:
1156:
1154:
1153:
1152:
1138:
1137:
1136:
1127:
1109:
1038:
794:
789:
748:
703:
675:
643:
587:
549:
481:
455:
418:Polybius square
412:
376:
368:
363:
317:Vigenère cipher
313:
304:
284:
279:
262:
247:
244:
239:
238:
218:
214:
205:
203:
196:
195:
191:
184:
165:
164:
160:
155:
116:Key progression
85:progressive key
49:Ibn al-Durayhim
41:
29:Vigenère cipher
17:
12:
11:
5:
1161:
1159:
1151:
1150:
1140:
1139:
1133:
1132:
1129:
1128:
1126:
1125:
1114:
1111:
1110:
1108:
1107:
1102:
1100:Random numbers
1097:
1092:
1087:
1082:
1077:
1072:
1067:
1062:
1057:
1052:
1046:
1044:
1040:
1039:
1037:
1036:
1031:
1026:
1024:Garlic routing
1021:
1016:
1011:
1006:
1001:
996:
991:
986:
981:
976:
971:
966:
961:
956:
951:
946:
944:Secure channel
941:
935:
934:
933:
922:
917:
912:
907:
905:Key stretching
902:
897:
892:
887:
882:
877:
872:
871:
870:
865:
855:
853:Cryptovirology
850:
845:
840:
838:Cryptocurrency
835:
830:
825:
824:
823:
813:
808:
802:
800:
796:
795:
790:
788:
787:
780:
773:
765:
758:
757:
754:
753:
750:
749:
747:
746:
741:
736:
722:
717:
711:
709:
705:
704:
702:
701:
696:
691:
685:
683:
677:
676:
674:
673:
668:
663:
657:
655:
649:
648:
645:
644:
642:
641:
636:
631:
626:
624:Reihenschieber
621:
616:
611:
606:
601:
595:
593:
589:
588:
586:
585:
580:
575:
570:
565:
559:
557:
551:
550:
548:
547:
542:
537:
532:
527:
522:
517:
512:
507:
502:
497:
491:
489:
483:
482:
480:
479:
474:
469:
463:
461:
457:
456:
454:
453:
448:
443:
438:
433:
428:
422:
420:
414:
413:
411:
410:
405:
400:
395:
389:
387:
385:Polyalphabetic
378:
370:
369:
364:
362:
361:
354:
347:
339:
325:
324:
319:
312:
309:
308:
307:
302:
282:
277:
260:
243:
240:
237:
236:
212:
189:
182:
176:. p. 26.
157:
156:
154:
151:
60:Alberti cipher
45:Al-Qalqashandi
40:
37:
33:Enigma machine
15:
13:
10:
9:
6:
4:
3:
2:
1160:
1149:
1146:
1145:
1143:
1124:
1116:
1115:
1112:
1106:
1105:Steganography
1103:
1101:
1098:
1096:
1093:
1091:
1088:
1086:
1083:
1081:
1078:
1076:
1073:
1071:
1068:
1066:
1063:
1061:
1060:Stream cipher
1058:
1056:
1053:
1051:
1048:
1047:
1045:
1041:
1035:
1032:
1030:
1027:
1025:
1022:
1020:
1019:Onion routing
1017:
1015:
1012:
1010:
1007:
1005:
1002:
1000:
999:Shared secret
997:
995:
992:
990:
987:
985:
982:
980:
977:
975:
972:
970:
967:
965:
962:
960:
957:
955:
952:
950:
947:
945:
942:
939:
936:
931:
928:
927:
926:
923:
921:
918:
916:
913:
911:
908:
906:
903:
901:
898:
896:
895:Key generator
893:
891:
888:
886:
883:
881:
878:
876:
873:
869:
866:
864:
861:
860:
859:
858:Hash function
856:
854:
851:
849:
846:
844:
841:
839:
836:
834:
833:Cryptanalysis
831:
829:
826:
822:
819:
818:
817:
814:
812:
809:
807:
804:
803:
801:
797:
793:
786:
781:
779:
774:
772:
767:
766:
763:
759:
745:
742:
740:
737:
734:
730:
726:
723:
721:
718:
716:
713:
712:
710:
708:Cryptanalysis
706:
700:
697:
695:
692:
690:
687:
686:
684:
682:
681:Steganography
678:
672:
669:
667:
664:
662:
659:
658:
656:
654:
650:
640:
637:
635:
632:
630:
627:
625:
622:
620:
617:
615:
612:
610:
607:
605:
602:
600:
597:
596:
594:
590:
584:
581:
579:
576:
574:
571:
569:
566:
564:
561:
560:
558:
556:
555:Transposition
552:
546:
543:
541:
538:
536:
533:
531:
528:
526:
523:
521:
518:
516:
513:
511:
508:
506:
503:
501:
498:
496:
493:
492:
490:
488:
484:
478:
475:
473:
470:
468:
465:
464:
462:
458:
452:
449:
447:
444:
442:
439:
437:
434:
432:
429:
427:
424:
423:
421:
419:
415:
409:
406:
404:
401:
399:
396:
394:
391:
390:
388:
386:
382:
379:
375:
371:
367:
360:
355:
353:
348:
346:
341:
340:
337:
333:
329:
323:
320:
318:
315:
314:
310:
305:
303:0-486-20097-3
299:
294:
293:
292:Cryptanalysis
287:
283:
280:
274:
269:
268:
261:
257:
256:
250:
246:
245:
241:
234:
230:
226:
225:Liber quintus
222:
216:
213:
202:
201:
193:
190:
185:
183:9780674985377
179:
175:
171:
170:
162:
159:
152:
150:
148:
145:
141:
140:cryptanalysis
137:
133:
129:
125:
120:
117:
112:
104:
100:
98:
94:
90:
86:
82:
79:—in his book
78:
74:
72:
71:
65:
61:
56:
54:
50:
46:
38:
36:
34:
30:
26:
22:
1055:Block cipher
900:Key schedule
890:Key exchange
880:Kleptography
843:Cryptosystem
792:Cryptography
614:One-time pad
487:Substitution
384:
291:
266:
252:
228:
224:
220:
215:
204:, retrieved
199:
192:
168:
161:
143:
121:
115:
113:
109:
106:Tabula recta
93:tabula recta
84:
80:
75:
68:
57:
43:The work of
42:
25:substitution
20:
18:
1043:Mathematics
1034:Mix network
666:Code talker
545:Running key
477:Four-square
132:Crimean War
70:cipher disk
994:Ciphertext
964:Decryption
959:Encryption
920:Ransomware
715:Cryptogram
609:Kama Sutra
578:Rail fence
573:Myszkowski
520:Chaocipher
472:Two-square
451:VIC cipher
403:Trithemius
255:David Kahn
242:References
984:Plaintext
639:Solitaire
377:by family
296:, Dover,
233:page 463.
1142:Category
1123:Category
1029:Kademlia
989:Codetext
932:(CSPRNG)
727:(Units:
563:Columnar
510:Beaufort
467:Playfair
441:Tap code
436:Nihilist
408:Vigenère
311:See also
288:(1939),
251:(1997),
206:13 April
200:Al-Kindi
53:Al Kindi
799:General
505:Autokey
393:Alberti
374:Ciphers
128:Babbage
39:History
910:Keygen
694:Grille
634:Slidex
568:Double
535:Pigpen
515:Caesar
500:Atbash
495:Affine
460:Square
446:Trifid
426:ADFGVX
398:Enigma
300:
275:
180:
940:(PRN)
689:Bacon
653:Codes
604:DRYAD
599:BATCO
592:Other
583:Route
540:ROT13
525:Great
431:Bifid
153:Notes
97:Latin
23:is a
731:and
699:Null
671:Poem
661:Book
530:Hill
298:ISBN
273:ISBN
208:2012
178:ISBN
134:and
58:The
733:Nat
729:Ban
144:See
62:by
1144::
172:.
149:.
19:A
784:e
777:t
770:v
735:)
358:e
351:t
344:v
186:.
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