概率积分及其在PUFFIN算法中的应用

积分分析是一种针对分组密码十分有效的分析方法,其通常利用密文某些位置的零和性质构造积分区分器.基于高阶差分理论,可通过研究密文与明文之间多项式的代数次数来确定密文某些位置是否平衡.从传统的积分分析出发,首次考虑常数对多项式首项系数的影响,提出了概率积分分析方法,并将其应用于PUFFIN算法的安全性分析.针对PUFFIN...

Probability Integral Cryptanalysis and Its Application on PUFFIN

Integral cryptanalysis is an effective method of block cipher analysis, and the integral distinguisher is usually constructed using a zero-sum property of some positions in the ciphertext. Based on the theorem of higher-order differential attack, the order of plaintexts can be exploited, to determine if some positions of the ciphertext are balanced. Inspired by the conventional integral cryptanalysis, the influence of constant on the leading-coefficient of polynomial is considered and the construction of probability integral distinguisher as well as the attack method are proposed in this study. When applied to PUFFIN, a 7-round probability integral distinguisher is constructed and used to mount a 9-round attack, and this attack can recover 92-bit round key. The data/time complexity is 2^24.8 chosen plaintexts, and 2^35.48 9 round encryptions, and the space complexity is 2²⁰.