摘要
H2-MAC是Kan Yasuda在ISC 2009上提出的一种新型的MAC结构,与HMAC的不同之处仅在于H2-MAC用固定的常数IV代替HMAC的外部密钥,计算MAC值时只访问一次种子密钥,在保持HMAC优势的基础上简化密钥管理。文中首次给出基于缩减到53(20-72)步的SHA-1的H2-MAC的等价密钥恢复攻击,并进行一般性伪造攻击(Universal Forger-y),证明取消外部密钥导致安全性降低。首先构造基于53(20-72)步SHA-1的H2-MAC的区分器,达成区分攻击,在区分攻击的基础上利用比特探测技术,恢复中间链接变量,即等价密钥,最后进行一般性伪造攻击。即在不知道密钥的前提下,攻击者可伪造任意消息M的合法MAC值,攻击的复杂度为299次MAC查询,远低于一般性伪造攻击的理想复杂度。
H2-MAC, which was proposed by Kan Yasuda in Information Security Conference （ISC） 2009, is a new type of MAC construction. Compared with HMAC, H2-MAC is much easier for algorithm imple- mentation and key management, for it gets access to the key only once. This paper first presents an equiv alent key recovery attack H2-MAC-SHA-1 reduced to 53 （20-72） steps, which conduces to a universal for gery attack directly. Firstly, an H2-MAC-SHA-1 distinguisher is constructed. Then, the intermediate chaining variable, i. e. , the equivalent key is recovered by using the distinguisher and bit flipping technolo gy. Consequently, the universal forgery attack is processed. The adversary unknowing the secret key can process the universal forgery attack by computing the valid MAC value of M, which can be an arbitrary message. The complexity of the attack is about 299 queries, which is much lower than the ideal complexity of the universal forgery.
出处
《空军工程大学学报（自然科学版）》
CSCD
北大核心
2013年第4期84-87,共4页
Journal of Air Force Engineering University(Natural Science Edition)
基金
高等学校博士学科点专项科研基金资助项目(20100131120015)
作者简介
张丽（1983-），女，安徽临泉人，博士生，主要从事密码学与信息安全研究．E—mail：lizhangj@mail．sdu．edu．cn
