In the existing authentication schemes, SIP messages are liable to multiple security hazards, such as attacks by abnormal messages, network data interceptions and analysis of ciphertexts.

• 摘要由于现有的认证机制不能有效解决会话初始协议(SIP)消息传送时网络侦听的问题，因此SIP网络传输时存在易遭受异常消息攻击、数据包被侦听、密文被分析等诸多安全威胁。