Abstract:

Salsa20 is one of the finalists of the eSTREAM project. Its main feature is using the ARX operations (i.e. addition, rotation, and xor on 32bit words) to achieve good confusion and diffusion effects. At present, many cryptanalytic results on it are statistical cryptanalysis and differential cryptanalysis. In this paper, we further investigate a differential fault analysis of Salsa20/256. By adopting a random fault word model, when inducing 96 faults,the 186 bit key can be recovered with a probability close to 1,accordingly the complexity of recovering the full key bits of Salsa20/256 can be reduced to 270, which implies that Salsa20/256 is sensitive to the differential fault analasis.

Key words: stream cipher;Salsa20;differential fault analysis