【摘要】 为了有效抵抗M Hell与T Johansson对基于带进位反馈移位寄存器(Feedback with carry shift Register,FCSR)的流密码的实时攻击,本文给出了一个使用密码学部件(FCSR)的新方法.在该方法中,只需要将FCSR的有效进位单元的内容与线性反馈移位寄存器(Linear Fedback Shift Regsiters,LFSR)的对应比特进行异或,随后即可执行原FCSR的运算.以新方法得到的组合部件的状态转移函数依然是二次的,因而对代数攻击和相关攻击有天然的免疫性,尤其重要的是理论分析与实验结果表明新的组合部件的所有进位单元的输出序列是独立的,无偏的,具有良好的统计特性,因而可以有效的阻止M Hell与T Johansson对基于FCSR的流密码的实时攻击以及其它类似攻击.更多还原

【Abstract】 We propose a novel FCSR-based cryptographic primitive for efficiently resisting M. Hell and T. Johansson’s real-time crypt-analysis on FCSR-based stream ciphers. With this proposed primitive in the application,we simply need to xor the bit in the carry unit with the corresponding state bit in a LFSR. Then just perform the original operation of the FCSR. Analysis and experimental results showthat: the transition function of the proposed primitive is still quadratic,thus it provides an intrinsic resistance to algebraic attacks and correlation attacks; and it is very important that all the sequences generated by the carry cells are independent,unbiased and have good statistical properties,thus can prevent the attack of Hell and Johansson and other similar attacks on FCSR-based stream ciphers.更多还原