Morbit

History

The Morbit cipher is similar to the Pollux cipher converting plaintext into morse code then the morse characters are converted into a numeric cipher based on a key. But each character in the morbit cipher represents two morse code characters rather than one. The Morbit cipher was developed by the American Cryptogram Association (ACA) member EUREKA and first appeared in the Jan-Feb 1964 edition of the ACA's magazine The Cryptogram. Its name is derived from Morse code, on which it is based, and the computer term binary digit or bit.

Description

To create the Morbit cipher a key is created based on a random 9-digit number or created from a keyword using the alphabetic order of letters as the key numbers. The position of each digit represents one of the 9 combinations of pairs of the three Morse code characters; '.' and '-' to represent the morse code symbols and 'x' to separate the morse groups. These pairs are placed vertically below the keyword.

For example using the keyword LOVEBIRDS the following table is produced:

L O V E B I R D S

5 6 9 3 1 4 7 2 8

. . . - - - x x x

. - x . - x . - x

The plaintext is then converted into morse code using the 'x' symbol to separate letters and 'xx' to separate words. If the number of characters is odd an 'x' is added to the end of the morse code. Finally each pair of morse symbols is replaced with the digit in the same column to create the cipher.

Example

Keyword: LOVEBIRDS (569314728)

Plaintext: Love is grand; divorce is a hundred grand.

l o v e i s g r a n d d i v o r

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

6 5 2 1 7 5 4 9 7 9 5 9 2 3 7 3 7 4 3 2 5 8 3 9 5 7 5 4 1 4 6 9

c e i s a h u n d r e d g r a n d

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

3 3 7 8 5 7 5 8 6 8 5 5 7 6 2 9 3 9 6 9 9 3 9 2 3 7 3 7 4 3 2 5

Ciphertext: 65217 54979 59237 37432 58395 75414 69337 85758 68557 62939 69939 23737 4325

Solving

Solving method: Brute force search.

All possible solutions are tested.