Research On Key Management Method In Secure Multicasting Communication

With the construction of broad network and widespread use of Internet, security multicast becomes leading development tread of communication, whose security is also the hot-spot topic in academe. The key problem of secure group communication is how to safely transmit decryption key to every legal user. The number of members varies dynamically when users join in or leave it along the whole group communication process. So it is important to update the session key for all the legal users. Therefore, the study on how to realize secure and efficient key management in group communication is more significant in both theory and practice.This paper analyses the theories and technologies concerning to key management in secure multicast communication. Secondly, this paper advances one new LKH method that Combined with RSA algorithm. In this algorithm, every user could calculate encrypted key by his private key. When anyone change its key, the group controller need't to encrypt the keys updated and then sent them out when users dynamic change, therefore this method can reduce the cost of updating key and solve the bottlenecks of large-scale multicast.In addition, this paper discusses how to prevent some lawless users from conspiring together, and advance the capability of multicast. Besides, the research on how to keep the balance of hierarchy that can keep the cost is the lowest.The theory and result of experiment prove the excellence of this method and the practicality. In the end, this paper implement the algorithm.