improved key recovery attacks on reduced-round salsa20 and chacha

ISCAS OpenIR

	improved key recovery attacks on reduced-round salsa20 and chacha
	Shi Zhenqing; Zhang Bin; Feng Dengguo; Wu Wenling
	2013
会议名称	15th International Conference on Information Security and Cryptology, ICISC 2012
会议录名称	Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)
页码	337-351
会议日期	November 28, 2012 - November 30, 2012
会议地点	Seoul, Korea, Republic of
收录类别	EI
ISSN	0302-9743
ISBN	9783642376818
部门归属	(1) Institute of Software Chinese Academy of Sciences Beijing 100190 China; (2) Institute of Information Engineering Chinese Academy of Sciences Beijing 100195 China
摘要	Salsa20 is a stream cipher designed by Bernstein in 2005 and Salsa20/12 has been selected into the final portfolio of the eSTREAM Project. ChaCha is a variant of Salsa20 with faster diffusion for similar performance. The previous best results on Salsa20 and ChaCha proposed by Aumasson et al. exploits the differential properties combined with the probabilistic neutral bits (PNB). In this paper, we extend their approach by considering a new type of distinguishers, named (column and row) chaining distinguishers. Besides, we exhibit new high probability second-order differential trails not covered by the previous methods, generalize the notion of PNB to probabilistic neutral vectors (PNV) and show that the set of PNV is no smaller than that of PNB. Based on these findings, we present improved key recovery attacks on reduced-round Salsa20 and ChaCha. Both time and data complexities of our attacks are smaller than those of the best former results. © 2013 Springer-Verlag.; Salsa20 is a stream cipher designed by Bernstein in 2005 and Salsa20/12 has been selected into the final portfolio of the eSTREAM Project. ChaCha is a variant of Salsa20 with faster diffusion for similar performance. The previous best results on Salsa20 and ChaCha proposed by Aumasson et al. exploits the differential properties combined with the probabilistic neutral bits (PNB). In this paper, we extend their approach by considering a new type of distinguishers, named (column and row) chaining distinguishers. Besides, we exhibit new high probability second-order differential trails not covered by the previous methods, generalize the notion of PNB to probabilistic neutral vectors (PNV) and show that the set of PNV is no smaller than that of PNB. Based on these findings, we present improved key recovery attacks on reduced-round Salsa20 and ChaCha. Both time and data complexities of our attacks are smaller than those of the best former results. © 2013 Springer-Verlag.
关键词	Security Of Data
语种	英语
内容类型	会议论文
URI标识	http://ir.iscas.ac.cn/handle/311060/15979
专题	中国科学院软件研究所
推荐引用方式 GB/T 7714	Shi Zhenqing,Zhang Bin,Feng Dengguo,et al. improved key recovery attacks on reduced-round salsa20 and chacha[C],2013:337-351.