A key management scheme for secure group communication using binomial key trees

Abstract

SUMMARYNumerous emerging applications, such as teleconferencing, board meetings, pay-per-view and scientifi c discussions, rely on a secure group communication model. Scalable group rekeying is an important issue in the secure group communication model as the nature of the group is dynamic. The number of encryptions performed and rekey messages constructed should be minimized to carry out updating of the group key, and secure delivery of the group key should be carried out in an effi cient manner. In this paper, we propose a new scheme to manage the secure group using the binomial key tree approach. In this scheme, the number of encryptions performed and rekey messages constructed during membership change are fewer compared to the scheme proposed by Wong and others. Further, it is not required to balance the tree after each membership change. We show that, for a large group, the average encryption cost and rekey message cost are independent of the size of the group for join operation and logarithmic in size of the group for leave operation. Hence our scheme is scalable.

Non-tree Based Group Key Management Scheme With Constant Rekeying and Storage Cost

“…In this sense, improved OFT scheme loses its intended advantage over LKH. Then, a centralized group key management scheme based on binomial key tree was proposed by Aparna et al [1]. The number of encryptions required for rekeying is log 2 n + 1 when a new user joins and 2 log 2 n − h − 1 (h = log 2 n/2 is the average height of the binomial key tree) when an existing user leaves the group.…”

“…In this section, the proposed group key management scheme is compared with some of the existing efficient tree based group key management schemes by Wong et al [21], Ku and Chen [11] and Aparna et al [1]. As discussed in section 2.1, the number of key changes, encryptions and rekey messages required for rekeying in these schemes upon user join/leave depends on the number of users in the group.…”

“…Also, the storage at the user and the KDC also depends on the number of users in the group. Table 5 shows the comparison of the proposed scheme with the schemes [21,11,1]. In comparison with these schemes, the storage and rekeying cost of the proposed scheme does not depend on the number of users in the group and is constant.…”

An efficient scheme to handle bursty behavior in secure group communication using binomial key trees

“…It handles only simultaneous leave operations. In References 16, 17, a binomial key tree (BKT) concept is used to manage a secure group and authors address the rekeying costs involved during join and leave operations. It is shown that the scheme is efficient in terms of the computation and communication costs.…”

“…It is shown that the scheme is efficient in terms of the computation and communication costs. In this paper, we address bursty behavior in SGC using the BKT scheme proposed in References 16, 17. We compute the number of new keys generated, encryptions performed, and rekey messages constructed for the worst case scenario.…”