Key management for Pay-TV broadcast systems in hierarchy
Shiuh-Jeng Wang, Pei-Shun Hu · Journal of Discrete Mathematical Sciences and Cryptography · 2006
In recent years, cable TV has enjoyed rapid growth and is now well established as one of the major broadcast media types. However, it is necessary to reinforce the security and confidentiality of current cable transmission data. In this paper, we introduce cryptographic accessing control into the architectural hierarchy of the Pay-TV system. The channels provided by the system can be categorized into various groups of a similar type. A subscriber to a specific group would be allowed to watch all channels within that group. In this way, the system’s key management is simplified and the private keys for accessibility to channels are reduced. Also, the access keys associated with each channel can be computationally derived and the updating procedure simplified. This means less time and lower costs are associated with the use of a hierarchical group structure. The access keys are then updated periodically during the month, depending on which day of the month the customer subscribed and paid for the service. The method we propose for a secure Pay-TV system with cryptographic key management has the following advantages including higher security, efficient encryption/decryption, hierarchy of groups and flexible key management.