Research Of Key Management Schemes In Wireless Sensor Networks

Wireless sensor networks (WSNs) have received a lot of attention due to their wide applications in military as well as civilian fields to this day. A WSN is composed of a large number of sensor nodes with limited power, computation, storage, and communication capabilities. Compared with the other networks, WSNs are vulnerable to various potential attacks, such as nodes capture attacks, Sybil attacks, false report injection attacks, replication attacks, eavesdropping, etc. So, security mechanism providing confidentiality, authentication, and data integrity is vital to ensure proper network operations.In security mechanisms, key management is the core of the issues. In recent years, many key management schemes have been proposed. In this dissertation, all new proposed key management schemes are aimed at lowing storage overhead, computation overhead and communication overhead, and improving local connectivity, the resilience against node capture attacks and the capability of defending against controlling compromised mobile nodes attacks and forging mobile nodes attacks, and achieving continuous secure management. So, our researches have more practical values.The major work and conclusions of present dissertation are as follows:1) In this dissertation, a security and efficient path-key establishment scheme is proposed.If direct key establishment between two neighbor sensor nodes fails, then they need to start the path-key establishment phase to establish a common key with the help of other sensor nodes. And path-key can improve security of common keys between two sensor nodes. So, path-key establishment is an important issue in a key management scheme. In path-key establishment process, we should take security and energy consumption into the comprehensive consideration. The path-key establishment scheme proposed in this dissertation comes to a compromise between security and energy consumption. Analysis and simulation shows that the scheme is efficient and security.2) This dissertation proposes a continuous security key management scheme.Adding new nodes to a WSN is necessary to ensure the WSN is in good working condition. However, how to ensure secure communications between the new added nodes and the original nodes of the WSN? That is, how to achieve continuous security management of WSNs? In this dissertation, an efficient and scalable key management scheme based on a combination of nodes’deployment knowledge, pre-distribution pairwise key and forward key chains is proposed. Theoretical and simulation analyses show that the scheme can increase local connectivity, and can improve the resilience against node capture significantly at low storage overhead (For the first deployment, the performance of the resilience against sensor nodes capture of the scheme is perfect. Except for the first deployment, if there are no nodes captured in bootstrapping phase, the performance of the resilience against node capture of the scheme is perfect too).3) In this dissertation, a continuous security key management scheme for Heterogeneous Wireless Sensor Networks (HWSNs) is proposed.Aiming at the security deficiency of the pre-distribution scheme for HWSNs, a security pairwise key establishment scheme based on a combination of deployment knowledge, backward key chain and rabin scheme is proposed. Analysis and simulation results show that the scheme makes much more improvement than the classical scheme for HWSNs on the memory overhead, the local connectivity, the resilience against node capture and so on.4) This dissertation proposes a scalable and efficient security scheme with multiple mobile sinks in WSNs.A WSN with multiple mobile nodes is controlled by mobile nodes. An attacker can easily take control of the entire network by controlling compromised mobile nodes and forging mobile nodes. So, proposing a security scheme against the above attacks is vital. In this dissertation, the proposed key management scheme for solving the above problems is based on the methods of updating keys. Analysis and simulation results show that the scheme can achieve high local connectivity at low cost memory overhead. In the scheme, the network is controlled by mobile nodes deployed recently. That is, if some sensor nodes deployed in some areas are controlled by an attacker, these sensor nodes will be free from the control when new mobile nodes are deployed in these corresponding areas.