Lightweight Key Agreement for Wireless Sensor Networks

Abstract

Due to the potentially unsecured environments in the wireless sensor networks (WSNs), protection from any attack is significantly important to maintain its health. Recently, many researchers have focused on providing the security to make sensor networks available and reliable for the nodes to securely communicate to each other. However, the message exchange for session key agreement is still high in computational requirements, and many messages need to be exchanged between principal nodes and trusted agents. In this paper, we propose a lightweight but secure method for node-to-node key agreement in unsecured WSNs. The main idea of the proposed key agreement is to compromise two trust agents-a registration server and a key server-to generate a session key for the principal nodes to communicate in the WSN environment. Due to the resource-constrained environments in WSNs, it is not appropriate to apply computationally expensive schemes that occur in asymmetric key encryption. Therefore, the proposed method is solely based on a symmetric cryptography protocol. The registration server provides a communication number for the principal nodes to communicate with the key server. The key server then generates a session key that principal nodes can securely communicate among each other. The proposed method allows two principal nodes to obtain the session key with less computation but secure in term of cryptography technique and message exchange with the trusted agents. Comparisons of security aspects with existing schemes are also provided in this paper. Finally, the confidentiality, authentication, integrity, and freshness of network security are discussed to analyze the performance of the proposed method.