Achieving Interoperability in Conditional Access Systems through the Dynamic Download and Execution of Cryptographic Software for the IPTV System

An IPTV system that transmits multimedia contents through the IP network needs to adopt a conditional access system allowing the only entitled subscribers to view the premium content as other pay-TV systems do. Although several standard specifications have been published for interoperable models of conditional access systems, the proposed models are based on the unidirectional or restricted bidirectional broadcasting network and do not utilize the characteristics of the IP network. However, software download scheme through the bidirectional IP network enables it to change existing conditional access systems in a secure way. This paper introduces an interoperable conditional access system that can update any cryptographic software provided by different conditional access system vendors through downloading and executing dynamically the downloaded conditional access software only if the software follows the pre-defined interfaces.