一种多变量公钥密码体制的安全性分析  

Cryptanalysis of a Multivariate Public Key Cryptosystem

作　　者：鲁刚 聂旭云[1,2,3] 秦志光 侯川勇[1,2] 

机构地区：[1]电子科技大学信息与软件工程学院,成都610054 [2]中国科学院信息工程研究所信息安全国家重点实验室,北京海淀区100093 [3]网络与数据安全四川省重点实验室,成都610054

出　　处：《电子科技大学学报》2018年第2期242-246,共5页Journal of University of Electronic Science and Technology of China

基　　金：国家"973"重点基础研究发展计划(2013CB834203);国家自然基金重点国际(地区)合作研究项目(61520106007);四川省科技支撑计划(2016GZ0065)

摘　　要：将"小域-大域"方法与三角形逐步迭代方法相结合,提出了一种新多变量公钥密码体制,并声称该体制能够抵抗秩攻击、线性化方程攻击和差分攻击。经过深入分析,发现该方案的中心映射满足大量一阶线性化方程。利用线性化方程可以将原体制转变为Square加密方案,然后利用差分攻击方案可恢复合法密文相应的明文。对于原体制的两种推荐参数,对于给定的公钥,恢复合法密文相应的明文复杂度分别约为2^(33)和2^(35)。上述攻击结果通过计算机实验得到了验证。In 2014, Yuan et al. proposed a new multivariate public key cryptosystem by combining “smallfield-big field” and “stepwise triangular” methods. The authors claimed that their scheme can be secure againstrank attack, linearization equation attack and differential attack. Through analysis, we found that there are a lot oflinearization equations satisfied by this scheme. We can transform it to an equivalent square encryption scheme bylinearization equation method and then recover corresponding plaintext for any given cipheretext by differentialattack. As to two recommended parameters, for given public key, the complexities of recovering plaintext are 233and 235, respectively. The results above are further confirmed by computer experiments.

关 键 词：差分攻击 线性化方程 多变量公钥密码体制 SQUARE 

分 类 号：TP309[自动化与计算机技术—计算机系统结构]