Study On Key Management Schemes For Wireless Sensor Network

Wireless Sensor Network (WSN) is a research focus at home and abroad nowadays, and can be applied to various fields. Security problems in different layers of WSN have attracted much attention with the development of WSN technology. Secure multicast and key management are included in the security of application layer. Key management provides the prevention mechanism for the security in lower layers of WSN and the key support for the security services such as privacy, authentication, integrity and security management. Key management is the basis of security encoding in physical layer, encryption or decryption in data link layer and network layer. The characteristic of WSN has decided that key management scheme (KMS) based on public key cryptography and key predistribution scheme (KPS) are generally adopted for WSN. However, the ideal results in connectivity, resistance, overhead and scalability can not be obtained by most proposed KPSs. Despite of high security, KMSs based on public key cryptography have great overhead so as to decrease the lifetime of sensor node. Aiming at the shortages in connectivity, security and node overhead of key management for WSN, KMSs are proposed to meet all four requirements in key predistribution and research the key management based on lightweight public key cryptography. Performance analyses for the presented KMSs are given. The research results are as follows.Two KPSs for heterogeneous sensor network are proposed:One is improved polynomial KPS, where two-parameter4th-order polynomial is kept secret to resist collusion attack and threshold attack, and then authentication mechanism guarantees the security during communication key establishment between any two cluster heads; The other is KPS based on Chinese Remainder Theorem (CRT) and LU matrix, where the CRT is used to secure the communication key between the cluster head and its any cluster member, and the communication key between any two cluster heads is generated with LU matrix. The analytical results show that there are remarkable advantages in connectivity, resistance, overhead and scalability in the presented two schemes. An identity-based KMS for WSN is proposed, where the node identity is used to generate the communication key. The Shannon Information Theory is used to build the attack model in the security proof. Moreover, the BDH problem is used as the computational complexity assumption and then the identity-based KMS is provable secure. The overhead analysis indicates that the proposed KMS has low storage and communication overhead. In addition, the overhead for each node is constant, so the scheme is scalable.An efficient certificateless signcryption (CLSC) scheme is proposed, where the parings are used to lead to a formal security proof. The presented CLSC scheme is IND-CCA2and EUF-CMA secure against the replacement attack and the master key attack without random oracles. Compared with the typical CLSC scheme, the reduction is tighter in the presented CLSC scheme. CLSC is necessary and feasible to key management for WSN. When the proposed CLSC scheme is applied to key management for WSN, the principle of communication key generation is similar to the identity-based KMS. However, the chosen random numbers in the two schemes are distinct. Key escrow problem does not exist in the key management for WSN based on the proposed CLSC scheme.