28:
103:
139:
message. To remedy this, some cipher disks now have multiple characters that stand for "end of word." Similarly a cipher disk may also have multiple characters that could be used for the letter "e" (the most common letter in
English) so that instead of having a character with a frequency of roughly 13%, there would be two characters that stood for "e" - each with a frequency of 6% or so. Users could also use a keyword so that all the characters including the letter e would change throughout the ciphertext.
114:, which was 3.75 inches (95 mm) in diameter and made of light yellow heavy card stock. It consisted of two concentric disks of unequal size revolving on a central pivot. The disks were divided along their outer edges into 30 equal compartments. The smaller inner disk contained letters, terminations and word pauses, while the outer disk contained groups of signal numbers. For easier recognition, the number eight represented two. The initials A.J.M. represent the Chief Signal Officer General
1051:
20:
65:
The first incarnation of the disk had plates made of copper and featured the alphabet, in order, inscribed on the outer edge of each disk in cells split evenly along the circumference of the circle. This enabled the two alphabets to move relative to each other creating an easy to use key. Rather than
126:
Cipher disks had many small variations on the basic design. Instead of letters it would occasionally use combinations of numbers on the outer disk with each combination corresponding to a letter. To make the encryption especially hard to crack, the advanced cipher disk would only use combinations of
74:
The cipher disk can be used in one of two ways. The code can be a consistent monoalphabetic substitution for the entire cipher or the disks can be moved periodically throughout the cipher making it polyalphabetic. For a monoalphabetic use, the sender and the person receiving the messages would agree
138:
When encoding a message using a cipher disk, a character is always used to mean “end of word.” The frequency of said character is abnormally high and thus easily detected. If this character, however, is omitted, then the words run together and it takes much longer for the recipient to read the
90:. An easy way to do this is for the sender and the recipient to agree that a certain number of characters into the message, the scales would be shifted one character to the right, repeating the procedure every (say) tenth letter. This would make it more difficult to crack, using
62:) consisting of two concentric circular plates mounted one on top of the other. The larger plate is called the "stationary" and the smaller one the "moveable" since the smaller one could move on top of the "stationary".
66:
using an impractical and complicated table indicating the encryption method, one could use the much simpler cipher disk. This made both encryption and decryption faster, simpler and less prone to error.
130:
Cipher disks would also add additional symbols for commonly used combinations of letters like "ing", "tion", and "ed". Symbols were also frequently added to indicate "and" at the end of a word.
127:
two numbers. Instead of 1 and 2 though, 1 and 8 were used since these numerals look the same upside down (as things often are on a cipher disk) as they do right side up.
79:
setting (e.g., the "G" in the regular alphabet would be positioned next to the "Q" in the cipher alphabet). The entire message is then encoded according to this key.
1031:
861:
36:
541:
258:
699:
147:
Since the 1930s, cipher disks have been labeled "decoders" and have been used for novelties. Many of the cipher disks that were
251:
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27:
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187:
Deavours, Cipher, et al. Cryptology: Machines, History & Methods. Norwood, MA: Artech House, 1989.
1021:
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8:
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164:
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83:
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111:
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76:
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102:
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732:
331:
32:
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148:
115:
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991:
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821:
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273:
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16:
Encryption and decryption tool consisting of two metal plates with alphabets
986:
826:
816:
806:
764:
708:
498:
212:
201:
The
History of Codes and Ciphers in the United States Prior to World War I
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851:
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920:
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51:
47:
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19:
836:
627:
607:
571:
561:
488:
361:
356:
351:
311:
291:
602:
597:
592:
526:
521:
473:
468:
463:
453:
427:
412:
397:
366:
316:
301:
516:
422:
407:
306:
54:
tool developed in 1470 by the
Italian architect and author
862:
Cryptographically secure pseudorandom number generator
228:
58:. He constructed a device, (eponymously called the
37:Thessaloniki Science Center and Technology Museum
1071:
86:, the cipher disk opened the way for convenient
693:
252:
203:. Vol. 20. Laguna Hills: Aegean Park P, 1978.
700:
686:
259:
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101:
69:
26:
18:
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1072:
681:
240:
190:
266:
13:
181:
142:
14:
1091:
1050:
1049:
707:
911:Information-theoretic security
206:
1:
174:
133:
106:Modern representation of the
97:
35:cipher disk, 5th century BC,
7:
1027:Message authentication code
982:Cryptographic hash function
785:Cryptographic hash function
158:
10:
1096:
906:Harvest now, decrypt later
222:New York: Doubleday, 1999.
1045:
1022:Post-quantum cryptography
974:
715:
677:
636:
580:
497:
446:
375:
272:
236:
232:
1012:Quantum key distribution
1002:Authenticated encryption
857:Random number generation
122:used for accountability.
1007:Public-key cryptography
997:Symmetric-key algorithm
790:Key derivation function
750:Cryptographic primitive
743:Authentication protocol
728:Outline of cryptography
723:History of cryptography
795:Secure Hash Algorithms
738:Cryptographic protocol
484:Siemens and Halske T52
199:Barker, Wayne G., ed.
123:
110:Cipher Disk, from the
88:polyalphabetic ciphers
82:In addition to simple
39:
24:
901:End-to-end encryption
847:Cryptojacking malware
547:Sectéra Secure Module
105:
70:Methods of encryption
56:Leon Battista Alberti
31:Reconstruction of an
30:
22:
1017:Quantum cryptography
941:Trusted timestamping
651:Intel SHA extensions
153:secret decoder rings
84:substitution ciphers
770:Cryptographic nonce
646:AES instruction set
165:Alberti cipher disk
92:statistical methods
60:Alberti cipher disk
23:A metal cipher disk
1080:Encryption devices
886:Subliminal channel
870:Pseudorandom noise
812:Key (cryptography)
124:
118:. Each disk had a
112:American Civil War
40:
25:
1067:
1066:
1063:
1062:
946:Key-based routing
936:Trapdoor function
802:Digital signature
673:
672:
669:
668:
638:Computer hardware
383:Bazeries cylinder
1087:
1053:
1052:
881:Insecure channel
733:Classical cipher
702:
695:
688:
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261:
254:
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167:, also known as
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1059:
1041:
970:
711:
706:
665:
632:
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493:
479:Lorenz SZ 40/42
442:
371:
268:
267:Cipher machines
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227:
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161:
145:
143:Popular culture
136:
100:
72:
17:
12:
11:
5:
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1032:Random numbers
1029:
1024:
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1004:
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994:
989:
984:
978:
976:
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956:Garlic routing
953:
948:
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933:
928:
923:
918:
913:
908:
903:
898:
893:
888:
883:
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876:Secure channel
873:
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866:
865:
854:
849:
844:
839:
834:
832:Key stretching
829:
824:
819:
814:
809:
804:
799:
798:
797:
792:
787:
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775:Cryptovirology
772:
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760:Cryptocurrency
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747:
746:
745:
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730:
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719:
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713:
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705:
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697:
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682:
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456:
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433:Reihenschieber
430:
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418:Jefferson disk
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274:Rotor machines
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189:
179:
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176:
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149:radio premiums
144:
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135:
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120:control number
116:Albert J. Myer
99:
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68:
15:
9:
6:
4:
3:
2:
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1081:
1078:
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1038:
1037:Steganography
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992:Stream cipher
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951:Onion routing
949:
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931:Shared secret
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823:
822:Key generator
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780:Hash function
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755:Cryptanalysis
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262:
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221:
219:
218:The Code Book
214:
209:
202:
196:
194:
184:
180:
170:
166:
163:
162:
156:
154:
151:were called "
150:
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109:
104:
95:
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80:
78:
67:
63:
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57:
53:
49:
45:
38:
34:
29:
21:
987:Block cipher
827:Key schedule
817:Key exchange
807:Kleptography
765:Cryptosystem
709:Cryptography
499:Secure voice
402:
292:M-125 Fialka
216:
213:Singh, Simon
208:
200:
183:
168:
146:
137:
129:
125:
81:
73:
64:
43:
41:
975:Mathematics
966:Mix network
447:Teleprinter
403:Cipher disk
52:deciphering
48:enciphering
44:cipher disk
926:Ciphertext
896:Decryption
891:Encryption
852:Ransomware
512:FASCINATOR
376:Mechanical
175:References
134:Weaknesses
98:Variations
77:cipher key
916:Plaintext
1074:Category
1055:Category
961:Kademlia
921:Codetext
864:(CSPRNG)
842:Machines
661:IBM 4764
656:IBM 4758
623:Pinwheel
159:See also
716:General
567:STU-III
552:SIGSALY
507:BID 150
459:BID 770
438:Scytale
362:Singlet
322:Mercury
169:formula
837:Keygen
628:Rockex
618:Purple
608:Noreen
572:VINSON
562:STU-II
532:NESTOR
489:SIGTOT
357:SIGCUM
352:SIGABA
312:Lacida
297:Hebern
287:Enigma
46:is an
33:Aeneas
872:(PRN)
603:KL-51
598:KL-43
593:KG-84
581:Other
527:KY-68
522:KY-58
474:KW-37
469:KW-26
464:DUDEK
454:5-UCO
428:M-209
413:Kryha
398:CD-57
367:Typex
347:SG-41
342:SG-39
317:M-325
302:HX-63
108:Union
75:on a
588:JADE
542:SCIP
537:OMNI
517:KY-3
423:M-94
408:HC-9
393:C-52
388:C-36
327:NEMA
307:KL-7
50:and
613:Red
557:STE
337:RED
332:OMI
282:CCM
155:."
1076::
215:.
192:^
94:.
42:A
701:e
694:t
687:v
260:e
253:t
246:v
220:.
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