摘要： 研究Yahalom协议及其变体，发现该系列协议存在的时序缺陷，给出一种利用此缺陷攻击Yahalom协议及其变体的方法。尽管Yahalom协议历经几次修改，且被证明不存在密钥泄露问题，但Yahalom协议及其变体仍然存在以前没有被关注过的时序缺陷。该文从时序角度对Yahalom-Paulson协议进行改进。改进后的协议保持了原协议的安全性，同时能抵御原来因时序缺陷所引起的攻击。

关键词: 安全协议, Yahalom协议, 协议时序, 时序缺陷, 安全攻击

Abstract: This paper researches the Yahalom protocol and its variants, finds a sequence flaw existing in them and provides a kind of method to attack them by using the flaw. The Yahalom protocol has been revised several times, and no key-compromise problem is proved in the final Yahalom-Paulson protocol, but the Yahalom protocol and its variants still have the sequence flaw which has never been paid attention before. The Yahalom-Paulson protocol is improved from the angle of sequence. The improved Yahalom-Paulson protocol preserves the security of the original protocol, and can resist the attack caused by the sequence flaw.

Key words: security protocol, Yahalom protocol, protocol sequence, sequence flaw, security attack

中图分类号: 

• TP309