Design And Implementation Of Server Of Group Key Management System

With the popularity of Internet, there emerge more and more broadband applications. Multicast has been rapidly developed. Compared with unicast and broadcast, multicast has three advantages: improving the data transport rate, decreasing the network congestion and alleviating the network load. But current multicast protocols lack secure mechanism to satisfied secure requirement in multicast applications. Secure group communication has become a hottest research topic. In the multicast communication, all members sharing the group key is the precondition of the secure communication. The group key is generated, distributed and rekeyed through the group key management, which is the key point of secure group communication.This paper accomplished the server's design of group key management system with the system's design and implementation principles. As the services provider of group key management system, sever mainly consists of three functional entities that are Policy Server, Group Controller and Key Server and Certified Manager .The server uses the Group Key Management Protocol program to implement the management of users, management of channels, management of key generation,key distribution,key update and the broadcast encryption. Not only do we achieve the goal of forward secrecy and backward secrecy of multicast, but also reduce the probability of cracking the key conspiracy.When the key updated, system uses application layer to multicast the key update message. It means the broadcaster receive the message and forward to the other group members. In this way server can reduce the cost.