Performance evaluation of secure group communication

There are demands for secure group communication on the internet, such as pay-per-view type broadcasting, business confidential information sharing and teleconference. Secure communication inside a group on an open network is critical to enhance the internet capability. The public key system is not sufficient to support the group security, since it is not scalable for large groups. Some researchers propose a scalable group security model, managing several common keys for encryption and decryption sharing inside the community. In this paper, we will evaluate the performance of this group security model. Using M/G/∞ queueing models and the basic queueing theory, we show how to find the optimal condition of the allocation of the common keys if the joins to group is a Poisson process. In addition, we show our optimal condition may work for more general arrival processes by using the cross covariance formula (a variant of Papangelou's formula) for the stochastic intensity of departure process.