A New Combinatorial Design Based Data En-Route Filtering Scheme for Wireless Sensor Networks

Wireless sensor networks are susceptible to report fabrication attacks, where adversary can use compromised nodes to flood the network with false reports. En-route filtering is a mechanism of dropping bogus/false reports while they are being forwarded towards the sink. Majority of the proposed en-route filtering schemes are probabilistic, where the originality of forwarded reports is checked with fixed probability by intermediate nodes. Thus, false reports can travel multiple hops before being dropped in probabilistic en-route filtering schemes. Few deterministic based en-route filtering schemes have also been proposed, but all such schemes need to send the reports through fixed paths. To overcome the above mentioned limitations of existing en-route filtering schemes, we propose a novel deterministic enroute filtering scheme. In the proposed scheme, secret keys are allocated to sensor nodes based on combinatorial design. Such design ensures direct communication between any two nodes without adding more key storage overhead. We provide in-depth analysis for the proposed scheme. The proposed scheme significantly outperforms existing schemes in terms of expected filtering position of false reports and is more buoyant to selective forwarding and report disruption attacks. Our scheme also performs neck-to-neck with existing schemes in terms of protocol overheads.