摘要：Problem statement: In a heterogeneous environment, for a secure multicast communication, the group members have to share a secret key which is used to encrypt/decrypt the secret messages among the members. The Secure Group Communication of large scale multicast group in a dynamic environment is more complex than securing one-to-one communication due to the inherent scalability issue of group key management. Since the group members are dynamic in nature such as joining or leaving the group, the key updating is performed among the valid members without interrupting the multicast session so that non group members can’t have access to the future renewed keys. Approach: The main aim is to develop a scheme which can reduce the cost of computational overhead, number of messages needed during the time of key refreshing and the number of keys stored in servers and members. The cost of establishing the key and renewal is proportionate to the size of the group and subsequently fetches a bottleneck performance in achieving scalability. By using a Cluster Based Hierarchical Key Distribution Protocol, the load of key management can be shared among dummy nodes of a cluster without revealing the group messages to them. Results: Especially, the existing model incurs a very less computational and communication overhead during renewal of keys. The proposed scheme yields better scalability because of the fact that the Key computational cost, the keys stored in key server and numbers of rekey-messages needed are very less. Conclusion: Our proposed protocol is based on Elliptic curve cryptography algorithm to form secure group key, even with smaller key size, it is capable of providing more security. This protocol can be used both in wired or wireless environments.
关键词：Clustering process; secure group communication; key management; Group Session Key (GSK); Domain Key (DK); complexity analysis
