摘要： 对辫群上密钥协商协议进行安全性分析，指出该协议无法抵抗中间人攻击，在密钥协商协议基础上，提出一种改进的密钥协商协议。该协议在密钥协商的过程中，采用辫群上的数字签名进行认证，有效防止中间人攻击和重放反射攻击。分析结果验证了该协议的安 全性。

关键词: 辫群, 共轭搜索, 密钥协商协议, 数字签名, 中间人攻击, 重放攻击

Abstract: A security analysis of a key agreement protocol on the braid group is made. The key agreement protocol is not reliable because it can not resist man in the middle attack. The detailed attack method is given. On the basis of the original protocol, an improved braid key agreement protocol is presented. By using the signature scheme on braid groups in the key agreement authentication process, the improved protocol can prevent man in the middle attack and replay attack effectively. Analysis result proves the security of the scheme.

Key words: braid group, conjugacy search, key agreement protocol, digital signature, man in the middle attack, replay attack

中图分类号: 

• TP309