Abstract: Hash function BLAKE is one of candidates for the second round SHA-3 competition,祠〕ch is based on modular addition, rotation and XOR that is called as ARX system commonly. It is a common belief that the mixture of the three operations gives a good primitive in designing cryptographic algorithm. By replacing modular addition with XOR,this paper researched lincarization of ARX system in BLAKE-32 algorithm, then, analyzed differential diffusibility of the algorithm after linearization and exploited some diffusion characteristics, furthermore, researched the probability of linear approximation of addition, and analyzed its validity on the algorithm. I}hc result shows that differential spreading does not satisfy the designers' declaration. On account of ARX in BLAKE, differential attack can be applied on BLAKE by local linearizing its core function.

Key words: Hash function, ARX, BLAKE algorithm, Lincarization, Differential attack