缩减轮数Crypton算法中间相遇攻击的改进  

Improved Meet-in-the-middle Attack on Reduced-round Crypton Cipher

作　　者：李永光[1,2] 曾光[1,2] 韩文报 

机构地区：[1]解放军信息工程大学,郑州450001 [2]数学工程与先进计算国家重点实验室,郑州450001

出　　处：《计算机科学》2015年第11期217-221,共5页Computer Science

基　　金：国家自然科学基金项目(61003291);数学工程与先进计算国家重点实验室开放课题(2013A03;2013A10)资助

摘　　要：Crypton密码算法是韩国学者提出的一种AES候选算法。通过研究Crypton算法的结构特征和一类截断差分路径的性质,利用差分枚举技术权衡存储复杂度和数据复杂度,提出了4轮和4.5轮中间相遇区分器。新的区分器减少了预计算表中的多重集数量,降低了存储复杂度。基于4轮区分器首次给出对7轮Crypton-128的中间相遇攻击,时间复杂度为2113,数据复杂度为2113,存储复杂度为290.72。基于4.5轮区分器首次给出对8轮Crypton-192的中间相遇攻击,时间复杂度为2172,数据复杂度为2113,存储复杂度为2138。Crypton cipher is one of the AES candidates proposed by korean scholars. This paper studied the structure of Crypton and the property of a class of truncated differential trail, used the differential enumeration technique to weigh memory complexity and data complexity, and proposed a new 4-round and 4. 5-round distinguishing property for the meet-in-the-middle attack on Crypton cipher, which can diminish the size of multisets stored in the pre-computed lookup table effectively,and lower the memory complexity. The first meet-in-the-middle attack on 7-round Crypton-128 based on the 4-round distinguishing property requires time complexity of 2113 , data complexity of 2113 , memory complexity of 290.72. The first meet-in-the-middle attack on 8-round Crypton-192 based on the 4. 5-round distinguishing property re- quires time complexity of 2172 , data complexity of 2113 , memory complexity of 2138.

关 键 词：Crypton密码 差分枚举技术 多重集 中间相遇攻击 

分 类 号：TN918.1[电子电信—通信与信息系统]