improved impossible differential cryptanalysis of reduced-round camellia

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	improved impossible differential cryptanalysis of reduced-round camellia
	Wu Wenling; Zhang Lei; Zhang Wentao
	2009
会议名称	15th International Workshop on Selected Areas in Cryptography
会议录名称	Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)
会议日期	AUG 14-15,
会议地点	Sackville, CANADA
出版地	HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY
出版者	SELECTED AREAS IN CRYPTOGRAPHY
ISSN	0302-9743
ISBN	978-3-642-04158-7
部门归属	Wu, Wenling; Zhang, Lei; Zhang, Wentao Chinese Acad Sci, State Key Lab Informat Secur, Inst Software, Beijing 100190, Peoples R China.
摘要	The block cipher Camellia has now been adopted as an international standard by ISO/IEC, and it has also been selected to be Japanese CRYPTREC e-government recommended cipher and in the NESSIE block cipher portfolio. Most recently, Wu et al constructed some 8-round impossible differentials of Camellia, and presented an attack on 12-round Camellia-192/256 in 5. Later in 6, Lu et al improved the above attack by using the same 8-round impossible differential and some new observations on the diffusion transformation of Camellia. Considering that all these previously known impossible differential attacks on Camellia have not taken the key scheduling algorithm into account, in this paper we exploit the relations between the round subkeys of Camellia, together with some novel techniques in the key recovery process to improve the impossible differential attack on Camellia up to 12-round Camellia-128 and 16-round Camellia-256. The data complexities of the two attacks are 265 and 289 respectively, and the time complexities of the two attacks are less than 2(111.5) and 2(222.1) respectively. The presented results are better than any previously published cryptanalytic results on Camellia without the FL/FL-1 functions and whitening layers.
关键词	Block Cipher Camellia Impossible Differential Cryptanalysis Round Subkey
主办者	AceCrypt, Int Assoc Cryptol Res
内容类型	会议论文
URI标识	http://ir.iscas.ac.cn/handle/311060/8214
专题	信息安全国家重点实验室
推荐引用方式 GB/T 7714	Wu Wenling,Zhang Lei,Zhang Wentao. improved impossible differential cryptanalysis of reduced-round camellia[C]. HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY:SELECTED AREAS IN CRYPTOGRAPHY,2009.