【摘要】 基于网络通信中对消息认证的需求,介绍了散列函数的基本概念及构造方法,讨论了其用于消息认证中必须满足的特性,分析了散列函数在消息认证中的使用方式。生日攻击是通用的碰撞攻击方法,它可用于攻击任何类型的散列函数。为了增强散列函数的抗碰撞能力,探讨了生日攻击的碰撞阈值和攻击步骤。最后提出了安全散列函数设计时宜采用迭代和压缩型结构,该算法的核心技术是设计无碰撞的压缩函数并重复使用,从而可增大攻击者的攻击难度。更多还原

【Abstract】 Based on the requirements of message authentication in network communication,basic concept and tectonic method of hash function is introduced,and its properties that must be satisfied in message authentication is discussed,and usage of hash function in message authentication is analyzed. The most important generic attack on the collision resistant is the birthday attack,it is used to attack all kinds of hash functions. To improve abilities of hash function in collision resistant,the collision threshold and attack process of birthday attack is studied. Finally,it is presented that the iterative and constringent structure should be adopted when hash functions is designed. The core technology of this algorithm need to design free-start collision resistant compression function which can be used repeatedly. Thus,the complexity for attackers is more difficult.更多还原