图7.3为杂凑函数的功能示意图 Hash functions were introduced in cryptology in the late, seventies as a too to protect the authenticity of information. Soon it be came clear that they were a very us eful building block to solve other se curity problems in 930206151063 telecommunic ation and computer networks. This pap er shet ches the history of the concept, discusses the applic ations of hash functions, and preents, the approaches that hav e been followed to construct hash functions.. 图73杂凑函数的功能 消息摘要的使用方式与消息认证码基本相同。消息摘要的使用方式与消息认证码基本相同。 图7.3为杂凑函数的功能示意图