This paper proposes a multiserver architecture for group key management to minimize the overall system bandwidth. The proposed system utilizes the dynamic split and merge with a low overhead where a physical server adaptively splits and merges its traffic into multiple groups, each served by a logical server so as to minimize its total bandwidth. The performance of this proposed approach is compared with that of the single-server case. The results show that multiserver architecture scales well when compared with the single-server approach.

Emerging applications, such as video conferencing, pay-per-view TV and stock market applications require data to be delivered securely from a single or multiple source to a group of recipients (Yang et al., 2001; Shankaran et al., 2003; and Hong and Ray, 2004). These applications are based on group communications model and have led to the design and implementation of secure multicast systems to provide efficient delivery of data. At the same time, there has been a significant growth in developing wireless networks that will free users from the confines of static communication networks. In order to offer forward and backward secrecy, a secure wireless multicast system must offer the following security features.

Authentication is the process of verifying the identity of a receiver before it joins a multicast group. One method that is currently in use for user verification is digital signature. Authentication can be done at both the sending end as well as the receiving end. Sender authentication verifies the identity of the sender and receiver authentication verifies the identity of the receiver (Chaddoud et al., 2001; and Roberto et al., 2003). Since the sender usually provides the service, in some multicast applications (such as video services) only receiver authentication is required.

Confidentiality allows only the legitimate users to share the data communicated to them. Unauthorized users, simply by eavesdropping, should not be able to make sense of the data. RSA encryption algorithm is generally used for this purpose in unicast environment. However, providing data confidentiality is much more difficult in wireless multicast environment due to the large group size and the dynamic nature of the group members (Junqi et al., 2003).

Integrity means detecting whether the data transmitted over the network is altered or not. One technique to achieve data integrity is using message digest (e.g., MD5). Generally, techniques that are used for unicast communication may also be directly applied for the wireless multicast environments.

Computer Sciences Journal, Wireless Environments, Multiserver Architecture Scales, Emerging Applications, Stock Market Applications, Group Communications Model, RSA Encryption Algorithm, Data Integrity, Wireless Multicast System, Wireless Networks, Data Encryption Key, Decryption Keys, Computer Communications.