Secure Group Key Management Scheme for Simultaneous Multiple Groups with Overlapped Memberships Using Binomial Key Tree

Abstract

The rich literature available for key management schemes for Secure Group Communication focuses on operating only a single group. We consider the operation of simultaneous/concurrent multiple groups in the Secure Group Communication model with overlapping memberships. Designing a secure key management scheme with efficient rekeying process in this scenario is a challenging task. We design an efficient secure group key management scheme for simultaneous multiple groups with overlapping memberships. We propose a new key structure called Binomial Key Tree Queue to manage the keys. Our scheme scales well as the overlapping memberships across the multiple groups increases. We compare the schemes with two schemes which have recently focused on key management protocol design for simultaneous multiple groups. The proposed scheme achieves significant reduction in rekeying cost, storage compared to these schemes. Interestingly, we achieve this efficiency in the rekeying cost without much increase in storage at user.