分组密码是信息安全中实现数据加密、认证和密钥管理的核心密码算法,其安全性分析是密码学的重要课题之一.基于差分分析原理,文中提出了分组密码新的分析方法:非对称不可能飞来器攻击.该方法是通过构造非对称不可能飞来器区分器,排除满足这种关系的密钥,并最终恢复出秘密密钥的一种攻击方法.利用密钥编排方案,基于差分表查询技术和数据多次利用技术,把新方法应用于AES-128.研究结果表明:攻击7轮AES-128所需的数据复杂度为2105.18个选择明文,时间复杂度为2115.2次加密,存储复杂度为2106.78个AES分组.就攻击轮数、数据复杂度和时间复杂度而言,新分析优于已有针对AES-128的攻击.
Block cipher is the core of cryptography that provides data encryption,authentication and key management in information security.The security of block cipher is an important issue in the cryptanalysis.Based on the principle of differential cryptanalysis,this paper introduces a new cryptanalytic technique on block cipher: asymmetric impossible boomerang attack.The technique used asymmetric impossible boomerang distinguisher to eliminate wrong key material and leave the right key candidate.With key schedule considerations,techniques of looking up differential tables and re-using the data,the authors apply asymmetric impossible boomerang attack to AES-128.It is shown that attack on 7-round AES-128 requires data complexity of about 2105.18 chosen plaintexts,time complexity of about 2115.2 encryptions and memory complexity of about 2106.78 AES blocks.The presented result is better than any previous published cryptanalytic results on AES-128 in terms of the numbers of attacked rounds,the data complexity and the time complexity.