随着OAuth2.0协议的广泛应用，其安全性受到了人们的重点关注. 为了增强OAuth2.0协议的安全性，本文首先引入数字签名技术，提出一个改进的OAuth2.0协议. 它支持授权服务器对资源拥有者和客户端的身份认证. 并且在计算模型下基于Blanchet演算，应用一致性对授权服务器认证资源拥有者和客户端进行建模，最后使用自动化工具CryptoVerif分析和证明了其认证性.
With the wide applicaitons of OAuth2.0 protocol, people have payed a special attention to its security. In order to enhance its security, in this study the digitial signature firstly is introduced, then an improved OAuth2.0 protocol is proposed which has the authentication from authorization server to client and authorization server to resource owner. At the same time based on the Blanchet calculus in computaional model, the correspondence is applied to model the authentication from authorization server to client and authorization server to resource owner, and finally the authentication is proved by CryptoVerif.