Lai-Massey结构伪随机特性研究  

On the Pseudorandomness of the Lai-Massey Scheme

作　　者：郭瑞[1] 金晨辉[1] 

机构地区：[1]解放军信息工程大学,郑州450004

出　　处：《电子与信息学报》2014年第4期828-833,共6页Journal of Electronics & Information Technology

基　　金：国家自然科学基金(61272488)资助课题

摘　　要：该文深入研究了Lai-Massey结构的伪随机特性。首先,证明了基于仿射几乎正形置换s设计的3轮LaiMassey模型并不具有伪随机特性,给出了Lai-Massey结构设计者所得结论的一个反例。其次,证明了双射s为任意正形置换时,至少3轮Lai-Massey结构才具有伪随机特性;证明了双射s为仿射正形置换时,至少4轮的Lai-Massey结构才具有超伪随机特性。结论表明,为构造伪随机特性更好的Lai-Massey结构实例,双射s最好设计为非线性的正形置换或几乎正形置换。The pseudoranness of the Lai-Massey schme is studied in this paper. First, itis proved that if ？ is an affine almost orthomorphism, 3-round Lai-Massey scheme can not reach the pseudorandomness, which is a counterexample of the Lai-Massey scheme designer,s result. Then, it is proved that at least 3-round Lai-Massey scheme is need for the property of pseudorandomness when the bijective ？ is an arbitrary orthomorphism, and at least 4-round Lai-Massey scheme is need for the property of super pseudorandomness when the bijective ？ is an orthomorphism. From the above results, it is preferable to design a bijective ？ which is nonlinear orthomorphism or almost orthomorphism to construct the Lai-Massey scheme with better pseudorandomness.

关 键 词：分组密码 伪随机特性 超伪随机特性 Lai-Massey结构 正形置换 

分 类 号：TN918[电子电信—通信与信息系统]