Location-aware key predistribution scheme for wide area wireless sensor networks

Abstract

Key predistribution in wireless sensor networks refers to the problem of distributing secret keys among sensors prior to deployment. Solutions appeared in the literature can be classified into two categories: basic schemes that achieve fixed probability of sharing a key between any pair of sensors in a network and location-aware schemes that use a priori knowledge about sensors' communication needs, such as location information, to guarantee connectivity only among sensors that need to and can talk. Location-aware schemes achieve performance enhancement over the basic schemes by using resources efficiently. However, existing location-aware solutions are not compatible with combinatorial methods that use a set of key groups to generate sensors' key rings. Combinatorial methods are appealing as they achieve deterministic performance close to optimal. Besides, existing location-aware solutions do not have enough flexibility in terms of trade-off between connectivity and resilience. In this paper we propose a general key predistribution framework that can use any key predistribution method as its underlying scheme, including combinatorial ones. The proposed framework provides the user with options on how to allocate available resources to achieve desired performance based on the needs of the application. We also consider heterogeneous sensor networks consisting of nodes with different amount of memory and communication ranges and show that special treatment of this case results in substantial performance improvement. We confirm the good performance of our framework by providing experimental and analytical results.