Huffman based conditional access system for key distribution in digital TV multicast

摘要

The advance of modern network technologies has made Digital TV systems available throughout the world. To provide secure media delivery in Digital TV systems, a large number of messages are exchanged for key updates in the conventional key distributed schemes of conditional access systems (CAS). In this paper, proposed a new multicast key distribution scheme based on Huffman grouping scheme of access control for conditional access system (CAS) in digital television multicast. The proposed key distribution scheme can greatly reduce the computation using fast Fourier transform and acquire higher efficiency and security using extended Euclidean algorithm. With this scheme, only authorized subscribers can watch the subscriber programs correctly. Unauthorized subscribers have no information to retrieve the correct programs over the networks. Moreover, the proposed scheme is more flexible in processing subscribers joining and leaving which is achieved by using Huffman based grouping scheme and is very important for service provider to dynamic manage the subscriber.