Pholkos算法的不可能差分分析  

Impossible Differential Cryptanalysis of Pholkos

作　　者：周锴[1,2,3] 王薇 ZHOU Kai;WANG Wei(School of Cyber Science and Technology,Shandong University,Qingdao 266237,China;Key Laboratory of Cryptologic Technology and Information Security,Ministry of Education,Shandong University,Qingdao 266237,China;Quan Cheng Laboratory,Jinan 250103,China)

机构地区：[1]山东大学网络空间安全学院,青岛266237 [2]山东大学密码技术与信息安全教育部重点实验室,青岛266237 [3]泉城实验室,济南250103

出　　处：《密码学报(中英文)》2025年第1期39-48,共10页Journal of Cryptologic Research

基　　金：国家重点研发计划(2018YFA0704702,2022YFB2701700);山东省自然科学基金(ZR2020MF053)。

摘　　要：Pholkos算法是Bossert等人在CT-RSA 2022会议上提出的一类可调整分组密码.本文将设计者给出的一条8轮不可能差分区分器一般化为一类8轮不可能差分区分器.基于8轮的区分器,构建11轮的密钥恢复攻击模型,给出攻击复杂度与8轮不可能差分活跃字节的位置及个数有关的表达式.结合密钥生成方案,选择合适的活跃字节位置,给出目前对Pholkos-256-256的攻击轮数最长的安全性分析结果,攻击的数据复杂度为2208.0个选择明文,时间复杂度为2185.5次11轮Pholkos-256-256加密,存储复杂度为2150.0个字节.Pholkos is a family of tweakable block ciphers proposed by Bossert et al.at CT-RSA 2022.This study generalizes an 8-round impossible differential proposed by the designer into a class of 8-round impossible differentials,and constructs a model of impossible differential attack on 11-round Pholkos.The formula of complexity of the impossible differential attack against 11-round of Pholkos-256-256 is presented depending on the active bytes of the 8-round distinguisher.Combined with the key expansion algorithm,the security analysis result is obtained of the longest round number against Pholkos-256-256 currently,with 2208.0 chosen-plaintexts,2185.511-round encryptions,and 2150.0 bytes memory.

关 键 词：分组密码 密码分析 不可能差分分析 Pholkos算法 

分 类 号：TP309.7[自动化与计算机技术—计算机系统结构]