ICE (cryptography)

ICE (Information Concealment Engine) is a algorithm of Chiffrement per block published by Matthew Kwan in 1997. The algorithm is similar in its structure with but with the presence of a permutation which depends on a key to each turn. The algorithm is not patented and the code was placed in the public domain.

ICE is based on a Réseau of Feistel with a Taille of block of 64 bits. The original algorithm uses a key of 64 bits and has 16 turns. A faster alternative, Thin-ICE uses only 8 turns. A generalized version, ICE-n uses 16· N turns with a key of 64· N bits.

Cryptanalyse

In 1998, Van Rompay and Al tried a attacks differential on Thin-ICE. With 2²³ clear texts chosen, the probability of finding the key is of 25%. With 2²⁷ texts, the probability goes up to 95%. For the original ICE, an attack on 15 of the 16 turns was found and requires with the more 2⁵⁶ selected clear texts.

References

Matthew Kwan, The Design off the ICE Encryption Algorithm, Fast Software Encryption 1997, pages 69-82.
Bart van Rompay, Lars R. Knudsen and Vincent Rijmen, Differential Cryptanalysis off the ICE Encryption Algorithm, Fast Software Encryption 1998, pages 270-283 (pdf).

External bonds

Page of ICE

Random links: