适用于双方频繁通信的密钥交换协议

首先对以前提出的一个高效的基于验证元的三方密钥交换协议进行了安全性分析，指出了它容易受到服务器密钥泄露攻击等安全威胁，且缺乏前向安全性；并以此为基础，针对大多数现存的基于验证元的3PAKE协议均难以抵御服务器密钥泄露攻击的现状，提出了一个新的3PAKE协议。通过安全性分析，证明了新协议比原协议更安全，能够抵御各种已知的攻击，且与现有的大多数同类协议相比具有更高的效率。

A novel key exchange protocol for frequent communication

Firstly, an efficient verifier based three party password authenticated key exchange protocol previously proposed is analyzed. The protocol is vulnerable to security threats such as server key disclosure attack and so on, and has a lack of forward secrecy. Secondly, on the basis of the analysis, in order to solve the problem that most of existing verifier based 3PAKE protocols cannot resist server key disclosure attack, a novel 3PAKE protocol is proposed. Through security analysis, the new protocol can be proved to be more secure than the old one, and has the ability to resist all known attacks. In addition, compared with existing protocols, it is more efficient.