Vehicle to Grid (V2G) networks are facing many security problems, such as privacy protection and identity authentication for electric vehicle (EV) users. To solve these problems of identity authentication in V2G networks, we propose a charging identity authentication scheme based on fog computing in this paper. In our proposed scheme, when each EV user finished his registration, all related servers must authenticate the users’ identities; also, when an EV user needs to start charging, the related fog server must authenticate his identity and save the related electricity information after charging. Further, the electricity server (ES) can periodically audit the electricity consumption from the fog servers in our scheme. Based on fog computing, the efficiency of our proposed V2G network charging scheme is improved by reducing the number of interactions between EV users and cloud servers. Also, we analyze the security of our proposed scheme, where our proposed scheme can use group signatures to protect the privacy of EV users. The experimental results show that our proposed scheme is effective and efficient.

车辆到网格（V2G）网络面临许多安全问题，例如隐私保护和电动汽车（EV）用户的身份认证。为了解决V2G网络中身份认证的这些问题，本文提出了一种基于雾计算的计费身份认证方案。在我们提出的方案中，当每个EV用户完成注册后，所有相关的服务器都必须对用户的身份进行身份验证；另外，当电动汽车用户需要开始充电时，相关的雾服务器必须验证其身份并在充电后保存相关的电量信息。此外，电力服务器（ES）可以定期审核我们方案中雾服务器的电力消耗。基于雾计算，通过减少EV用户与云服务器之间的交互次数，我们提出的V2G网络计费方案的效率得以提高。此外，我们分析了我们提出的方案的安全性，其中我们提出的方案可以使用组签名来保护电动汽车用户的隐私。实验结果表明，该方案是有效的。