Enhanced TKTOFT protocol for ternary tree based distributed group key management in cognitive radio networks

Cognitive radio networks provide solution to inefficient utilization of spectrum resources present in current wireless communication networks. Group key management techniques are used to secure communication among nodes in cognitive radio networks. This paper analyses total number of nodes that are pruned and renewed in ternary key tree during batch rekeying to measure the communication overhead. With this analysis, this paper proposes and implements an enhanced version of TKTOFT protocol (ETKTOFT) with modified batch rekeying scheme. From the simulation results, it is inferred that the proposed ETKTOFT protocol computationally outperforms SKM method and TKTOFT protocol by reducing the rekeying time to 57.16% and 15.14% respectively. Further, the proposed protocol generates 18% lesser number of renewed nodes than existing TKTOFT protocol thus reducing the communication overhead. As the proposed protocol minimizes both computation and communication overhead, it in turn can reduce the energy consumed by wireless mobile devices used in group oriented applications, thus increasing their lifetime.