几类流密码基本部件的设计与分析

发布时间：2018-02-22 20:29

本文关键词： 流密码线性反馈移位寄存器非线性反馈移位寄存器布尔函数能量分析　出处：《西安电子科技大学》2014年博士论文　论文类型：学位论文

【摘要】：流密码具有结构简洁、加密速度快、错误传播有限等特点,广泛用于高速数据传输与加密。基于硬件的流密码更因低功耗特性,在资源受限环境下发挥着无可替代的作用。本文对流密码的几类基本部件:线性反馈移位寄存器、非线性反馈移位寄存器和布尔函数进行了研究和分析,取得以下主要成果:(1)通过分析线性反馈移位寄存器延迟序列和初始状态间的关系,给出了能够完全抵抗能量攻击所需触发器数目的下界。提出了一种线性反馈移位寄存器设计方案,在抵抗线性反馈移位寄存器能量攻击时,附加触发器的个数至多为5个,有效降低了线性反馈移位寄存器的附加功耗。(2)针对基于非线性反馈移位寄存器和布尔函数的流密码算法,通过分析输出布尔函数和非线性反馈移位寄存器反馈函数的Walsh谱值,提出了一种基于Walsh谱的非线性部件的密码分析方法。在分析平衡性、非线性度、相关免疫度等密码学指标基础上,查找影响函数密码学性质的关键Walsh谱值点,对存在问题的谱值点进行函数值分析,判断算法是否符合安全性要求。最后利用该方法对流密码Grain v1进行了分析,通过Walsh谱分布指出了算法中存在的安全隐患。(3)重点研究了定义在2nZ上的4值广义Bent函数。给出了一种2nZ上4值Bent函数的构造方法,该方法主要用于生成奇数个变元的广义Bent函数。然后,通过布尔置换,给出了奇变元广义Bent函数的具体实现方法。(4)通过分析Bent函数的函数值和游程特性,提出了一种基于真值表的Bent函数搜索算法,与其他搜索算法相比,该方法具有较低的存储复杂度,易于使用并行计算实现等特点。
[Abstract]:Stream cipher is widely used in high-speed data transmission and encryption because of its simple structure, fast encryption speed and limited error propagation. In this paper, some basic components of convection cipher, namely linear feedback shift register, nonlinear feedback shift register and Boolean function, are studied and analyzed. By analyzing the relationship between the linear feedback shift register delay sequence and the initial state, In this paper, the lower bound of the number of flip-flop which can resist energy attack completely is given. A design scheme of linear feedback shift register is proposed. When resisting the energy attack of linear feedback shift register, the number of additional flip-flops is up to 5. The additional power consumption of linear feedback shift register is reduced effectively. (2) aiming at the stream cipher algorithm based on nonlinear feedback shift register and Boolean function, the Walsh spectral value of the output Boolean function and nonlinear feedback shift register feedback function is analyzed. This paper presents a cryptographic analysis method for nonlinear components based on Walsh spectrum. Based on the analysis of cryptographic indexes such as balance, nonlinearity and correlation immunity, the key Walsh spectrum points affecting the cryptographic properties of functions are found. The spectral value of the problem is analyzed to determine whether the algorithm meets the security requirements. Finally, the method is used to analyze the convection cipher Grain v1. Based on the Walsh spectrum distribution, the security hidden danger in the algorithm is pointed out. (3) the 4-valued generalized Bent function defined on 2nZ is studied, and a method of constructing 4-valued Bent function on 2nZ is given. This method is mainly used to generate generalized Bent functions of odd variables. Then, by Boolean permutation, the concrete implementation method of singular variable generalized Bent functions is given. A Bent function search algorithm based on truth table is proposed. Compared with other search algorithms, this method has lower storage complexity and is easy to be implemented by parallel computing.
【学位授予单位】：西安电子科技大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TN918.2

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