摘要
本文首先分析差分故障攻击的故障模型与原理,利用S盒的差分不均匀性,通过建立输入差分、输出差分和可能输入值之间的对应关系,给出差分故障分析的优化方案,实现快速归约,提高差分故障攻击的效率.本文通过对LBlock算法建立对应关系,可以快速直观缩小输入值取值空间,进而快速确定对应扩展密钥.对于不同故障值(输入差分),对应的输出差分和可能输入值均不相同,可以得到二元关系集合.由于轻量级分组密码S盒多为4×4 S盒,该集合中元素较少,注入少量不同故障值,通过查表,对可能输入值取交集即可快速确定唯一可能输入值.将优化方案应用于LBlock轻量级分组密码算法,在最后一轮输入处注入2次宽度为16 bit的故障可恢复最后一轮轮密钥,然后将状态回推一轮,在倒数第二轮输入处注入2次宽度为16 bit的故障可恢复倒数第二轮密钥.根据密钥扩展方案,恢复两轮轮密钥后将恢复主密钥的计算复杂度降为2^(19).
Firstly, this paper analyzes the fault model and principle of differential fault attack. By using the differential inhomogeneity of S-boxes, this paper gives an optimization of differential fault analysis by establishing the corresponding relationship between input differentials, output differentials,and possible input values to improve the efficiency of differential fault attack. In this paper, the corresponding relationship for LBlock algorithm is established, which can be used to effectively reduce the value space of input values, and then quickly determine the corresponding extended key. For different fault values(input differentials), the corresponding output differences, and possible input values are not the same, there exists a set of binary relationships. Since the lightweight S-boxes are mostly 4 × 4 S boxes, there are fewer elements in the set and a small number of different false values are injected. By looking up the table, the only possible input value can be quickly identified by taking the intersection of possible input values. The optimization scheme is applied to the LBlock lightweight block cipher algorithm. In the last round of input, two 16-bit wide faults are recoverable to the last round key, and then the state is pushed one round back. In the second last round, by injecting 2 faults in 16-bit width, the second last round key can be recovered. According to the key expansion scheme,the recovery of two-round key reduces the computational complexity of recovering master key to 219.
作者
王涛
王永娟
高杨
张诗怡
WANG Tao;WANG Yong-Juan;GAO Yang;ZHANG Shi-Yi(Information Engineering University,Zhengzhou 450001,China)
出处
《密码学报》
CSCD
2019年第1期18-26,共9页
Journal of Cryptologic Research
基金
国家自然科学基金(61872381)~~
