密码学报2018，Vol.5Issue(2)：126-139,14.DOI:10.13868/j.cnki.jcr.000225
改进的SKINNY算法的不可能差分分析
Improved Impossible-differential Cryptanalysis of Reduced-round SKINNY
摘要
Abstract
SKINNY is a new family of lightweight AES-like tweakable block ciphers proposed by Beierle et al. at CRYPTO 2016. It is one of the proposals following the Tweakey framework,and can be divided into 6 different versions based on the tweakey size and block size. This paper evaluates the security of SKINNY against impossible-differential analysis under single-key conditions. First, we found 16 truncated impossible differentials with the longest length of SKINNY that reaches 11 rounds by using miss-in-the-middle technique, when there is one active cell in the input and output of the distinguisher. Second, we choose one of the truncated impossible differentials and present an impossible-differential analysis on 20-rounds of SKINNY-64-128 under the single-key conditions. We utilize the properties of the S-box difference and the properties of the Mixcolumn operation of SKINNY to perform key guessing attack. By using the"periodical property"in the tweakey schedule,we derive some linear relationships between subtweakeys,and reduce the number of subtweakeys to guess during the analysis from 45 to 33. Finally, the parallel attack technique and early abort technique are used to effectively reduce the time complexity of the attack. Our attack requires 229chosen plaintexts and 294nibbles of memory and performs 2119.3SKINNY encryptions. Compared with the existing results of impossible differential analysis on SKINNY, the number of chosen plaintexts and time complexity are both reduced.关键词
分组密码/SKINNY算法/不可能差分分析/并行攻击技术/早夭技术Key words
block cipher/SKINNY/impossible-differential cryptanalysis/parallel attack technique/early abort technique分类
信息技术与安全科学引用本文复制引用
洪豆,陈少真..改进的SKINNY算法的不可能差分分析[J].密码学报,2018,5(2):126-139,14.基金项目
信息保障技术国家重点实验室开放课题(分组密码组件特性及应用研究)The Fund of Science and Technology on Information Assurance Laboratory(The Research on the Component Properties and Applications of Block Cipher) （分组密码组件特性及应用研究）
