Syllabary
History
The Syllabary cipher, also known as the Syllabary Square, was described in Military Cryptanalytics Part 1 Chapter XI, April 1956 by William F. Friedman and Lambros D. Callimahos and later in the US Army Field Manual No 34-40-2 dated September 1990.
Description
It consists of a 10x10 grid containing individual letters of the alphabet, digits 0 to 9 and 64 frequent digraphs and trigraphs. To the left side of the grid and above it the digits 0-9 are placed in order or randomly to mark the row and column numbers. The grid is filled with the alphabet letters, digits and syllables in alphabetical order or a keyword is used followed by the unused letters and syllables of the alphabet in alphabetical order. The digits are placed immediately after the single letters A-J with 1 following A, 2 following B and so on up to 0 following J. Cipher text is produced by replacing the letters, syllables and digits of the plain text by the row/column numbers of the grid.
There are three variations of the Syllabary cipher:
Unknown Coordinates/Known Key square - The key square is filled in alphabetical order and the row/column numbers are placed in random order.
Known Coordinates/Unknown Key square - The key square is filled using a keyword and the row/column numbers are placed in numeric order (0-9).
Unknown Coordinates/Unknown Key square - The key square is filled using a keyword and the row/column numbers are placed in random order.
7 0 3 1 4 6 5 9 8 2
1 A 1 AL AN AND AR ARE AS AT ATE
8 ATI B 2 BE C 3 CA CE CO COM
2 D 4 DA DE E 5 EA ED EN ENT
9 ER ERE ERS ES EST F 6 G 7 H
3 8 HAS HE I 9 IN ING ION IS IT
5 IVE J 0 K L LA LE M ME N
7 ND NE NT O OF ON OR OU P Q
0 R RA RE RED RES RI RO S SE SH
4 ST STO T TE TED TER TH THE THI THR
6 TI TO U V VE W WE X Y Z
Unknown Coordinates/Known Keysquare
A key feature of the syllabary cipher is that the letters, digraphs and trigraphs of the keyword, and plaintext, can be separated in different ways, each producing different cipher text. For example using the key word REPLACING can produce a grid starting with the following:
R E 5 P L A 1 C 3 I 9 N G 7
RE P L A 1 C 3 IN G 7
RE P L A 1 C 3 ING
RE P LA C 3 IN G 7
... and many others.
Using the keyword, REPLACING, and the left and top keys as 1829357046 and 7031465982 respectively, produces the following table:
7 0 3 1 4 6 5 9 8 2
1 RE P LA C 3 ING A 1 AL AN
8 AND AR ARE AS AT ATE ATI B 2 BE
2 CA CE CO COM D 4 DA DE E 5
9 EA ED EN ENT ER ERE ERS ES EST F
3 6 G 7 H 8 HAS HE I 9 IN
5 ION IS IT IVE J 0 K L LE M
7 ME N ND NE NT O OF ON OR OU
0 Q R RA RED RES RI RO S SE SH
4 ST STO T TE TED TER TH THE THI THR
6 TI TO U V VE W WE X Y Z
The plaintext is converted to the cipher by locating the letters or syllables in the table and using the row and column numbers as the ciphertext.
Example
Key square keyword: REPLACING
Left keyword: 1829357046
Top keyword: 7031465982
Plaintext: A friend is one who dislikes the same people that you dislike.
Plaintext: A f ri e nd is on e w h o d i s l i k e st h e
Ciphertext: 15 92 06 28 73 50 79 28 66 31 76 24 39 09 59 39 55 28 47 31 28
Plaintext: s a me p e o p l e th a t y ou d is l i k e
Ciphertext: 09 15 77 10 28 76 10 59 28 45 15 43 68 72 24 50 59 39 55 28
Ciphertext: 15920 62873 50792 86631 76243 90959 39552 84731 28091 57710 28761 05928 45154 36872 24505 93955 28
Example to Try
93 83 03 91 84 92 05 91 83 71 08 51 58 80 83 43 88 66 57 97 55
02 54 00 66 12 10 49 35 65 33 50 07 83 33 84 20 88 10 59 65 65 59 70 92 10 59 59 91 54 83 97 02 52 97
97 07 71 12 16 92 10 57 05 91 83 10 90 83 28 52 91 88 69 49 65 59 64 90 91 83 69 37
00 12 16 91 85 70 81 69 81 50 12 92 70 81 60 10 90 21 59 59 64 90 02 74 52
70 49 65 65 01 83 25 16 83 54 60 74 12 07 71 53 40 92 25 36 13 55 77 16 49 25 16 44 82
62 81 65 16 84 40 92 01 80 70 81 65 55 92 16 84 29 16 40 33 92
29 66 25 16 74 52 70 49 65 65 10 40 31 28 59 72 24 51 83 40 47 10 71 03 92 03
40 93 03 71 25 73 50 02
Source:
Solving
Solving method: Hill Climbing.
The Syllabary cipher solver can be used to solve the following types:
Unknown Coordinates / Known Key square
Known Coordinates / Unknown Key square
Standard syllabary key squares are provided for a number of different languages; English, French, German, Italian, Latin and Spanish. If another language is selected the program defaults to the English key square. The key squares are those published on the ACA website at http://www.cryptogram.org/resource-area.