An enhanced key management scheme based on key infection in wireless sensor networks

We propose an enhanced key management scheme based on Key Infection, which is lightweight scheme for tiny sensors. The basic scheme, Key Infection, is perfectly secure against node capture and eavesdropping if initial communications after node deployment is secure. If, however, an attacker can eavesdrop on the initial communications, they can take the session key. We use common neighbors for each node to generate the session key. Each node has own secret key and shares it with its neighbor nodes. Then each node can establish the session key using common neighbors' secret keys and a random number. Our scheme needs only a few communications even if it uses neighbor nodes' information. Without losing the lightness of basic scheme, it improves the resistance against eavesdropping on the initial communications more than 30%.