Incentive-Based Optimal Nodes Selection Mechanism for Threshold Key Management in MANETs with Selfish Nodes

Most of the previous work on threshold-cryptography-based distributed CA concentrates on the initial systems configurations and concrete protocols design, ignoring the efficiency and effectiveness of the key management service during its operation, and always assuming that there are honest nodes to carry out the service faithfully. This paper focuses on developing a selection mechanism in MANETs with selfish nodes, to dynamically select a coalition of nodes carrying out the threshold key management service optimally during system operation. First, we formulate the dynamic nodes selection problem as a combinatorial optimization problem, with the objectives of maximizing the success ratio of key management service and minimizing the nodes' cost of security and energy. Then, to ensure truth telling is the dominant strategy for any node in our scenario, we extend the payment structure of the classical Vickrey-Clarke-Groves (VCG) mechanism design framework and divide the payment into pieces to the nodes, with the consideration of their actual execution effectiveness. Simulations show that the proposed mechanism enjoys improvements of both the success ratio of key management service and lifetime of the network, as well as reductions of both the cost of participating nodes and compromising probability of MANETs, compared with the existing work.