Patent ID: 6307939
Filing Date: 2001-10-23
Classification: H04N

Abstract:
Process for assigning a complementary conditional access to a television program already in conditional access, this television program initially comprising:video and/or sound and/or data components, scrambled according to a first conditional access system (SysA), the scrambling operation making use of cryptographic processing using control words (CW),entitlement control messages (SysA ECM) expressing the conditions for marketing the program,entitlement management messages (SysA EMM) composed of data managing entitlements acquired by the user, andpossibly a set of data identifying services offered (PSI, SI) and/or extending the description of the program offer,characterized by the fact that:this program is received in means containing access entitlements corresponding to the first conditional access system (SysA),the control words (CW) used for scrambling are reproduced,complementary access control messages (SysB ECM) are calculated starting from these reproduced control words (CW), taking account of the conditions of the complementary conditional access system (SysB), and complementary access control messages are built up (SysB ECM),complementary entitlement management messages (SysB EMM) are produced specific to the complementary conditional access system (SysB), possibly together with a complementary set (SysB EPG) identifying services offered in the complementary conditional access system,the program is rebroadcast with its components unchanged, its access control messages (SysA ECM) and its entitlement management messages (SysA EMM) unchanged, and possibly all initial television program data identifying offered services and/or adding to the description of offered programs, and complementary access control messages (SysB ECM), complementary entitlement management messages (SysB EMM), and possibly the set of complementary data (SysB EPG) specific to the complementary conditional access system (SysB), are added.