VIC cipher
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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 can be regarded as the evolutionary pinnacle of the Nihilist cipher family. It has several components, including mod 10 chain addition (a lagged Fibonacci generator, a recursive formula used to generate a sequence of pseudorandom digits), 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.
[edit] External links
- John Savard's page on the VIC cipher
- PPC-XX, a variant with four different keying methodes
- SECOM, a VIC variant with extended checkerboard
[edit] See also
| Classical cryptography |
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| Rotor machines: CCM | Enigma | Fialka | Hebern | HX-63 | KL-7 | Lacida | M-325 | Mercury | NEMA | OMI | Portex | SIGABA | SIGCUM | Singlet | Typex |
| Ciphers: ADFGVX | Affine | Alberti | Atbash | Autokey | Bacon | Bifid | Book | Caesar | Four-square | Hill | Keyword | Nihilist | Permutation | Pigpen | Playfair | Polyalphabetic | Polybius | Rail Fence | Reihenschieber | Reservehandverfahren | ROT13 | Running key | Scytale | Solitaire | Straddling checkerboard | Substitution | Tap Code | Transposition | Trifid | Two-square | VIC cipher | Vigenère |
| Cryptanalysis: Frequency analysis | Index of coincidence |
| Misc: Cryptogram | Polybius square | Scytale | Straddling checkerboard | Tabula recta |
| Cryptography |
| History of cryptography | Cryptanalysis | Cryptography portal | Topics in cryptography |
| Symmetric-key algorithm | Block cipher | Stream cipher | Public-key cryptography | Cryptographic hash function | Message authentication code | Random numbers |
