摘要： Skype 正越来越普及，并受到越来越多的关注。文章从通信安全的角度来分析Skype 的安全特性，介绍了Skype 通信加密的过程，讨论Skype 使用加密的具体技术细节，在此基础上分析鉴定用户服务器身份以保护通信信息的安全，分析了几种常见攻击对Skype 的可行性，对Skype 的通信安全进行概括，并提出了使用中应注意的安全事项。

关键词: 高级加密标准；非对称加密算法；重放；中间人攻击

Abstract: Skype is becoming more popular, and receives more many attention. This paper analyzes Skype’ security feature from the communications security, introduces the process of Skype correspondence keeping secret, discusses the technique details of cryptography, under this foundation analyzes authenticating user and server identities to protect the content transmitted across the P2P network from disclosure by parties other than the peers, analyzes the possibilities of a few familiar attacks, carries on the summary to the Skype correspondence safety, and puts forward some safe items that should notice while using.

Key words: AES; RSA; Relay; Man-in-the-middle attacks