Vesta-2M流密码的密码分析

Cryptanalysis of the Vesta-2M stream cipher

分析了俄国商用密码Vesta-2M流密码的安全性。流密码Vesta-2M的密钥流发生器的初始密钥规模为)2(536O。本文指出文献[1]中攻击方法的错误,并提出一种已知明文攻击方法,所需明文量很小(约几百比特),计算复杂度的上界为)2(372O。

The security of stream cipher Vesta-2M used in commercial products in Russia is analyzed. The size of the initial key of the keystream generator of stream cipher Vesta-2M is)2(536O. The author point out the mistake of attack introduced by the paper [1], and introduce a known plaintext attack method where only a small segment of known plaintext(about hundreds of bits) , the upper bound of the compute complexity is)2(372O.