STEF: A secure ticket-based en-route filtering scheme for wireless sensor networks

Node compromise is a serious threat in wireless sensor networks. An adversary can use compromised nodes to inject false data into the network forging events to deceive the base station. Furthermore, an adversary can cause serious damage by injecting a large amount of false messages to deplete the scarce energy resources of the forwarding en-route sensor nodes. In this paper, we propose a Secure Ticket-Based En-route Filtering Scheme (STEF) that drops false messages en-route. We propose a ticket concept where reply messages are only forwarded if they contain a valid ticket originally issued by the base station. Messages containing no ticket, or an replayed ticket, are immediately filtered out by not compromised sensor nodes. The ticket concept is based on lightweight one-way functions. This enables every en-route node to verify the tickets. Furthermore, our scheme does not need symmetric key sharing between message generating nodes and en-route nodes, which results in a high resiliency against node compromises. Our security and performance analysis shows that STEF provides a high security level and is very efficient in saving energy. Furthermore, the required storage capacity on the sensor nodes is very low.