PREFACE vii Preface IP multicast is an efficient solution for group communication over the Internet, as both the sender resources and the network bandwidth are relieved with the aid of this emerging technology. However, this superiority suffers, when the group communication must fulfill some security requirements. An essential issue relates to sharing the communication key. Particularly, this k...

Scalable group key management (also known as group rekeying) schemes proposed in the literature can be classified into three categories: stateful schemes, stateless schemes and self-healing schemes. These schemes differ mainly on the interdependency of rekey messages and rekeying overhead. Logical key hierarchy (LKH) based approaches are stateful in that members should have received past rekeyi...

Scalable group rekeying schemes proposed in the literature can be classified into three categories: stateful schemes, stateless schemes and self-healing schemes. They differ mainly on the interdependency of rekey messages and messaging overhead in rekeying. Logical key hierarchy (LKH) based approaches are stateful in that members should have received past rekeying messages to decrypt current re...

In secure multi-party communications, the Logical Key Hierarchy scheme has been proved to be communication optimal for large groups. However, this scheme still suffers from an expensive rekeying cost when the group is very dynamic. To reduce the rekeying cost, Zhu et al. suggested to partition the logical key tree in two sub-trees based on the duration of each member in the multicast group. Alt...

Rapid growth of Internet spawns many group oriented multicast applications like Internet pay TV, news dissemination and stock quote system. The fortes of these applications are the support of dynamic, scalable group membership and group members are geographically divergent. As members of the group move in and out, an imperative cryptographic rekeying model should be applied to preserve the conf...

In this paper, we study the rekeying issue in IEEE 802.16e WiMAX networks. The existing rekeying scheme the Multicast and Broadcast Rekeying Algorithm (MBRA) unicasts new keys to each subscriber station (SS). This scheme does not scale well since it incurs large communication overheads when the number of SSs increase. In our work, first we propose a general tree-based rekeying scheme, which is ...

This paper describes support for batch rekeying in Mykil, a key management system for supporting secure group multicast. Batch rekeying in Mykil allows for substantial reductions in the cost and complexity of rekeying operations, arguably the expensive portion of the system. By accumulating join and leave operations and utilizing an algorithmic approach to minimize the number of necessary rekey...

In this paper, we study the rekeying issue in IEEE 802.16e WiMAX networks. The existing rekeying scheme—the Multicast and Broadcast Rekeying Algorithm (MBRA) unicasts new keys to each subscriber station (SS). This scheme does not scale well since it incurs large communication overheads when the number of SSs increase. In our work, first we propose a general tree-based rekeying scheme, which is ...

In group communication scenario, key management is important to preserve forward and backward secrecy. In order to achieve it keys need to be changed during user join/leave which is done by an operation called rekeying. In a centralized key management scheme, the server thereafter passes the new keys to the existing users who are affected via unicasts and multicasts. The number of unicasts and ...

An important problem for secure group communication is key distribution. Most of the centralized group key management schemes employ high rekeying cost. Here we introduce a novel approach for computation efficient rekeying for multicast key distribution. This approach reduces the rekeying cost by employing a hybrid group key management scheme (involving both centralized and contributory key man...