1 2 3 4 5 1 U N Ij T E KW=United States Of 2 D S A O F America 3 M R C B G 4 H K L P Q i/j = same cell 5 V W X Y Z repeats omitted PT: g o t a c i g a r e t t e ? CT: 35 24 14 23 33 13 35 23 32 15 14 14 15 Russians memorized the proper numbers and "talked" at about 10-15 words per minute. One of the advantages was that it afforded communication by a great variety of media - anything that could be dotted, knotted, pierced, flashed or indicate numerals in any way could be used. The innocuous letter was always suspicious. Ciphertext letters were indicated by the number of letters written together; breaks in count by spaces in handwriting; upstrokes, downstrokes, thumbnail prints, all subtly used to bootleg secrets in and out of prisons. The system was universal in penal institutions. American POW's used it in Vietnam. Transposition of the KW provided a further mixed alphabet: B L A C K S M I T H D E F G N O P Q R U V W X Y Z taken off by columns: B D V L E W A F X C G Y K N Z S O M P I Q T R H U the Polybius square would be: 1 2 3 4 5 1 B D V L E 2 W A F X C 3 G Y K N Z 4 S O M P I 5 Q T R H U The Nihilists, so named for their opposition to the czarist regime, added a repeating numerical KW . Making the cipher a periodic similar to the Vigenere but with additional weaknesses. Let KW = ARISE 22 53 45 41 15 PT: bomb winter palace NT: 11 42 43 11 21 45 34 52 15 53 44 22 14 22 25 15 Key: 22 53 45 41 15 22 53 45 41 15 22 53 45 41 15 22 CT: 33 97 88 52 36 67 87 97 56 68 66 75 59 63 40 37 or with bifurcation: 33978 85236 67879 75668 66755 96340 37774 nulls=774 NIHILIST TRANSPOSITION A simpler form of the Nihilist was in double transposition. The PT was written in by rows (or diagonals); a KW switched the rows; a same or different KW switched the columns, and the resulting CT was removed by columns or by one of 40 or more routes out of the square. ex: KW = SCOTIA or 524631 PT: let us hear from you at once concerning jewels xxxx Transpose by Columns S C O T I A 5 2 4 6 3 1 1 S E U H T L (let us h) 2 R A F O R E 3 A Y U T O M 4 A N E B C O 5 E U J W T O 6 X L X X S E Transpose by Rows 1 2 3 4 5 6 S 5 E U J W T O C 2 R A F O R E O 4 A N E B C O T 6 X L X X S E I 3 A Y U T O M A 1 S E U H T L X= bad choice for nulls The resulting cryptogram is: E U J W T O R A F O R E A N E B C O X L X X S E A Y U T O M S E U H T L. (message length and 5th group are entries to solution) Clues to cryptanalysis of the Nihilist systems were reconstructing the routes, evenness of distribution of vowels, period determination and digram/trigram frequency in CT. The USA Army for many years used a similar system. RUSSIAN LANGUAGE NOTE Every language has a frequency distribution. A prime difficulty for English speaking students of Russian is the scarcity of linguistic cognates in the two languages. Russian is more complex than other romantic languages which have many common word derivatives. The highly inflected Russian grammar aids rather than hinders the cryptographer by supplying him with valuable tools for decrypting.