VIC cipher - Definition and Overview

The VIC cipher was a pencil and paper cipher used by the Soviet spy Reino Hayhanen, codenamed "VICTOR".

It was arguably the most complex hand-operated cipher ever seen. Although certainly not as complex or secure as modern computer operated stream ciphers or block ciphers, in practice messages protected by it resisted all attempts at cryptanalysis by at least NSA (and perhaps other organizations such as GCHQ) from its discovery in 1953 until Hayhanen's defection in 1957.

The VIC cipher has several components, including a base 10 lagged Fibonacci generator, a straddling checkerboard, and a disrupted double transposition. Until the discovery of VIC, it was generally thought that a double transposition alone was the most complex cipher an agent, as a practical matter, could use as a field cipher.

External links

• John Savard's page on the VIC cipher (http://home.ecn.ab.ca/~jsavard/crypto/pp1324.htm)

See also: Topics in cryptography.