IPTV CAS using efficient group key management scheme

IPTV service provider only allows the users authorized by CAS to access to the contents. In CAS, hierarchical key structure is used to manage users efficiently and securely. The amount of message transmission for key update increases as the number of users goes up. In this paper, we propose the IPTV CAS using group key management scheme based on bottom-up hash tree. The proposed scheme can update key using one message regardless of the number of users.