Design of Secure Group Key Management Scheme for Multicast Networks Using Number Theory

This paper proposes a scheme to provide security to dynamic multicast VoIP systems efficiently. Security is usually provided by encrypting the media packets sent from a user to other users with the help of a shared key called the session encryption key (SEK). The most time consuming process in a dynamic multicast VoIP environment is the group key management. Whenever there is a change in the group membership, the key needs to be updated and the updated key has to be sent to all active members in the group. Hence, by decreasing the number of update messages required for an updated key, the performance of the system can be improved considerably, thus making the scheme more efficient. The proposed secure multicast key management scheme combines the advantages of logical-key tree structure and Chinese remainder theorem (CRT) to achieve an effective scheme. This paper compares the efficiency of the proposed scheme with the existing schemes and the comparison shows that the proposed scheme performs better than the existing schemes in terms of reduction in key update messages.