Lightweight key distribution and management method for sensor networks

A lightweight security framework is disclosed that combines PKI with symmetric key cryptography to exploit the system asymmetry in hierarchical sensor networks. The framework provides protocols for public key exchange, session and group key generation, pair-wise key generation, and network resource protection in a low-cost security architecture. The security framework shifts much of the security-related computational load off of the resource-constrained sensor nodes and on to resource-rich base station nodes. The method is based on the generation and management of two kinds of symmetric keys from a set of bootstrapping asymmetric keys on each node.