An Authentic Key Management Scheme for Hierarchical Wireless Sensor Networks

Key Management is a critical security service in wireless sensor networks (WSNs). It is an essential cryptographic primitive upon which other security primitives are built. The most critical security requirements in WSNs include authentication and confidentiality. These security requirements can be provided by a key management but it is difficult due to the ad hoc nature, intermittent connectivity, and resource limitations of the sensor networks. In this paper we propose an authenticated key management (AKM) scheme for hierarchical networks based on the random key pre-distribution. Further, a secure cluster formation algorithm is proposed. The base station periodically refreshes the network key, which provides the following: a) the authenticated network communication, and b) a global and continuous authentication of each network entity. Multiple level of encryption is provided by using two keys: 1) a pair-wise shared key between nodes, and 2) a network key. The AKM scheme is more resilient to node capture as compared to other random key pre-distribution schemes. The proposed key management scheme can be applied for different routing and energy efficient data dissemination techniques for sensor networks