A survey of key management for secure group communication

Group communication can benefit from IP multicast to achieve scalable exchange of messages. However, there is a challenge of effectively controlling access to the transmitted data. IP multicast by itself does not provide any mechanisms for preventing nongroup members to have access to the group communication. Although encryption can be used to protect messages exchanged among group members, distributing the cryptographic keys becomes an issue. Researchers have proposed several different approaches to group key management. These approaches can be divided into three main classes: centralized group key management protocols, decentralized architectures and distributed key management protocols. The three classes are described here and an insight given to their features and goals. The area of group key management is then surveyed and proposed solutions are classified according to those characteristics.