【摘要】 为了对分组加密算法SMS4进行新的安全性分析,基于SMS4的轮结构中的活跃字变化的特点,选择1个特定的明文形式来构造1个含3个活跃字的∧集,通过观察平衡字的传播路径,在第9轮找到了1个平衡字,由此构建出1个新型的12轮区分器并对14轮SMS4进行Square攻击.研究结果表明:攻击所需的明文数据量为232,计算复杂度为296.5,这说明14轮SMS4对Square攻击是不免疫的.更多还原

【Abstract】 In order to make a new security evaluation for the block cipher SMS4,a certain plaintext is chosen to built a gamma set that contains three active words.Based on the character of the diversification of the active words in the round structure of SMS4,a balance word is found in the ninth round by observing the spread path of the balance words,and therefore a new 12-round distinguisher is constructed,by use of which a 14-round square attack is made on SMS4.In the attack 232chosen plaintexts are needed and the time complexity is about 296.5.Thus the 14-round SMS4 is not immune to the Square attack.更多还原