Research on Cryptosystems and Their Criteria

近年来，针对密码系统的攻击层出不穷。针对DES或FEAL的差分密码分析和线性密码分析都是很强的攻击方法。密码攻击的报告在工业组织中有很大的影响力，因此，我们估计了到目前为止出现的密码攻击的强度，以建立安全的密码系统。我们的研究结果是：（a）随机数发生器强度的估计，以及估计工具的开发;（B）在个人计算机中使用事件的随机定时的安全随机数发生器的建议;（c）在快速并行机上的大数因子分解，及其对Cunningham计划的报告;（d）对指数型加密算法的定时攻击的估计，（e）关于版权安全代理的建议，以及（f）关于安全密钥分发系统的建议。

Recently, many attacks against cryptosystems have been reported. Differential cryptanalysis and linear cryptanalysis against DES or FEAL are very strong attack methods. The reports of cryptattac have very serious influence among industrial organizations.Hence, we estimated the strength of cryptattacks presented so far, to make secure cryptsystems. Our research results are,(a) estimation of the strength of random number generators, and development of a tool of the estimation,(b) proposal of secure random number generators using random timing of events in personal computers,(c) factorization of large numbers at fast pararell machine, and its report to Cunningham Project,(d) estimation of timing attack against exponential type encryption algorithms,(e) proposal of security agents for copyright, and(f) proposal of secure key distribution systems.