摘要: 对Eric Filiol提出的采样攻击方法(Proc. of INDOCRYPT’00, Springer-Verlag出版, 2000)进行改进,利用n级LFSR序列的已知相似序列的2个不同起点的d采样序列,同时攻击2个Ld级LFSR序列,得到2Ld个关于n级LFSR初态的线性无关的线性方程,再攻击LFSR初态的其余n2Ld个比特,从而恢复n级LFSR的初态。改进后的采样攻击方法计算复杂性由Eric Filiol采样攻击的C(Ld)+C(nLd)降为2C(Ld)+C(n2Ld)。
关键词:
序列密码,
采样序列,
采样攻击
Abstract: This paper improves the decimation attacks method presented by Filiol. By d-decimating the known sequence from two different initial points, it can attack the initial states of two Ld-series LFSR, obtaining 2Ld independent equations with the bits of the initial state of the n-series LFSR, then attacks the other n2Ld bit of the n-series LFSR initial states, consequently recovers the initial states of the n-series LFSR. The computational complexity of improved decimation attack is reduced from C(Ld)+C(nLd) of decimation attacks presented by Filiol to 2C(Ld)+C(n2Ld), where C(m) is the computational complexity of attacking m-series LFSR by correlation attacks or fast correlation attacks.
Key words:
stream cipher,
decimation sequence,
decimation attacks
中图分类号:
祁传达;陈越奋;王丽娜. 序列密码采样攻击的改进方法[J]. 计算机工程, 2009, 35(8): 155-157.
QI Chuan-da; CHEN Yue-fen; WANG Li-na. Improved Method for Decimation Attacks of Stream Cipher[J]. Computer Engineering, 2009, 35(8): 155-157.