Recently, smart cities have become more and more popular as a way to enhance society and the standard of living for its people. These are the results of the increased social and economic prospects that the advancement of information and communication technology (ICT) has brought about. But there are certain issues with our presumptions about privacy and security. The usage of cellphones and other technologies has already enhanced people’s engagement and sense of connection. Gadgets, smart energy meters, and security appliances are commonplace these days. The Internet of Things will soon be fully connected to homes, public spaces, healthcare systems, and other social institutions. In this work, we improve the security performance of communication networks in smart cities by implementing a novel framework and scheme to guarantee strong data secrecy and authentication. The smart city system can set up shared session key procedures and mutual authentication to secure a two-way communication channel between the control center and smart meters. Our comprehensive simulation was used to test and evaluate the security performance of the smart city communication network both with and without our suggested technique. Throughput, latency, load, and traffic received packets per second were all measured. The resources available in our suggested solution were further limited by the fact that we used a network intrusion detection system (NIDS) and a man-in-the-middle (MITM) attack to evaluate and validate the security criteria.