The Russian VIC Cipher

Hollow nickel message

Probably the most notorious pencil-and-paper cipher was the VIC cipher, named after Soviet spy Reino Hayhanen, codename Victor. In 1953, the FBI discovered a code message on a microfilm in a hollow nickel.

All attempts to break the message failed. Hayhanen eventually revealed the method to decipher the message when he defected in 1957. This cipher shows how strong encryption can be, without any crypto device or computer program.

The cipher used a date, a random number, and a 20 letter keyphrase to encrypt the message. The keyphrase was divided into two groups and transformed into a serie of numbers. Combined with the date and random number, they were used to generate 50 random digits by chain addition. The ten last digits were then used as header for a straddling checkerboard. The text is converted from letters into digits with this checkerboard.

A transposition, also based on the keyphrase, date and number, was used to generate a series of digits. Some of the generated digits served as a sequence header for a first simple transposition of the text (which was already encrypted with the checkerboard) and another part of the generated digits served as a header for a more complex disrupted transposition.

Despite being a pencil-and-paper cipher, it proved to be a highly secure cipher and the strongest ever, known to be issued for use in the field. Only Hayhanen's information enabled the FBI to reveal the content of the secret message.

More on the Hayhanen story can be found on the FBI site. A detailed description by David Kahn of  the original message and the VIC cipher is found in the CIA library, titled Number One From Moscow. Another example is found at John Savard's site. The SECOM cipher, similar to the VIC cipher, also uses a straddling checkerboard and double disrupted transposition, is found on my website.