电子学报2017，Vol.45Issue(4)：966-973,8.DOI:10.3969/j.issn.0372-2112
LBlock-s算法的不可能差分分析
Impossible Differential Cryptanalysis of Reduced-Round LBlock-s
摘要
Abstract
LBlock-s is the kernel block cipher of the authentication encryption algorithm LAC submitted to CAESAR competition.The general structure of LBlock-s is almost the same as that of LBlock,but LBlock-s adopts an improved key schedule algorithm with better diffusion property.Using the shifting relation of subkeys derived by the key schedule algorithm,an impossible differential cryptanalysis on 21-round LBlock-s was presented based on a 14-round impossible differential.The time and data complexities are 2.67.61 21-round encryptions and 2.63 chosen plaintexts respectively,and the number of subkey bits needed to be guessed is 72.Using partial-matching method,an impossible differential cryptanalysis on LBlock-s up to 23-round was also presented with time complexity less than exhaustion of all key bits.This work is useful for the security analysis of LAC algorithm.关键词
LBlock算法/LBlock-s算法/密钥扩展算法/不可能差分分析Key words
LBlock/LBlock-s/key schedule algorithm/impossible differential cryptanalysis分类
信息技术与安全科学引用本文复制引用
贾平,徐洪,来学嘉..LBlock-s算法的不可能差分分析[J].电子学报,2017,45(4):966-973,8.基金项目
国家自然科学基金(No.61100200,No.61170235,No.61309017,No.61472251,No.61502524,No.61521003,No.U1536101) （No.61100200,No.61170235,No.61309017,No.61472251,No.61502524,No.61521003,No.U1536101）
国家863高技术研究发展计划(No.2015AA01A708) （No.2015AA01A708）
