Pollux

History

A Pollux cipher is one of the Morse code based ciphers and was mentioned in Cryptanalysis: A Study of Ciphers and Their Solution, first published as Elementary Cryptanalysis, 1939 by Helen Fouché Gaines (1888-1940).

Description

The cipher converts plaintext into morse code then each morse character into a number based on a key. The key is 10 characters long and consists of a random mixture of three characters; '.' and '-' to represent the morse code symbols and 'x' to separate the morse groups. It is recommended that four dots and three of the other two symbols are used in the key. For example write the key, such as x.--.x.-x., below the numbers 1-0 to produce the following table:

1 2 3 4 5 6 7 8 9 0

x . - - . x . - x .

The plaintext is then converted into morse code using the 'x' symbol to separate letters and 'xx' to separate words. Finally each morse symbol is replaced with one of the digits representing the symbol to create the cipher.

Example

Key: x.--.x.-x.

Plaintext: When one teaches, two learn.

Key: 1234567890

x.--.x.-x.

w h e n o n e t e a c h e s t w o l e a r n

.--x....x.x-.xx---x-.x.xx-x.x.-x-.-.x....x.x...xx-x.--x---xx.-..x.x.-x.-.x-.

5381075067142664849876016497904640326257067677519460346884665805629739787130

Ciphertext: 53810 75067 14266 48498 76016 49790 46403 26257 06767 75194 60346 88466 58056 29739 78713 0

Solving

Solving methods: Brute force search.

All possible solutions are tested.