The ubiquitous nature of the Internet is enabling a new generation of applications to support collaborative work among geographically distant users. Security in such an environment is of utmost importance to safeguard the privacy of the communication and to ensure the integrity of the applications. Secure group communications (SGC) refers to a scenario in which a group of participants can receive and send messages to group members in a way that outsiders are unable to glean any information, even when they are able to intercept the messages. SGC is becoming extremely important for researchers and practitioners because many applications that require SGC are now widely used, such as teleconferencing, telemedicine, real-time information services, distributed interactive simulations, collaborative work, grid computing, and the deployment of virtual private networks. Even though considerations are necessary.