TASK: Template-Based Key Assignment for Confidential Communication in Wireless Networks

Predistribution of cryptographic keys is a widely used approach for establishing secure communication between network nodes which are severely resource-constrained. Many proposed key predistribution schemes make the implicit assumption that message contents need not be kept private from nodes other than the intended recipient. Messages in such schemes are not guaranteed to be confidential--they may be read by nodes within the network other than the intended recipient. In this paper, we present TASK--a symmetric key predistribution scheme that enables secure and confidential communication within wireless networks. TASK distributes keys by generating and reinforcing a series of template key assignment instances. We show, through analysis and simulation, that TASK achieves a level of security superior to that of two recently proposed schemes that also provide confidentiality, while maintaining the same space complexity. TASK is also parameterized, which allows it to make use of key storage capacities that other recently proposed schemes cannot.