This letter claimed that Mahmood et al.’s scheme still exhibited some vulnerabilities. Concretely, their scheme cannot withstand an impersonation attack and fails to realize perfect forward secrecy and mutual authentication with the absence of the trusted authority. Moreover, their scheme could suffer from an ephemeral key compromise attack under the CK threat model. We, therefore, fixed those weaknesses and proposed a new security-enhanced scheme where we changed the session keys’ format and added robust authentication between the smart meter and utility control. The computation cost, however, is higher in the new scheme (seen in Appendix D) and we do not solve the key escrow problem. In the future, we wish to design protocol with computation cost declined and give solutions to the key escrow problem for the smart grid infrastructure.

这封信声称 Mahmood 等人的计划仍然存在一些漏洞。具体而言，他们的方案无法承受模拟攻击，并且无法在缺乏可信权威的情况下实现完美的前向保密和相互认证。此外，他们的方案可能会遭受 CK 威胁模型下的临时密钥泄露攻击。因此，我们修复了这些弱点并提出了一种新的安全增强方案，我们更改了会话密钥的格式并在智能电表和公用事业控制之间添加了强大的身份验证。然而，新方案的计算成本更高（见附录 D），我们没有解决密钥托管问题。未来，我们希望设计计算成本下降的协议，并为智能电网基础设施的关键托管问题提供解决方案。