CONDITIONAL ACCESS DATA DECRYPTING SYSTEM

摘要

The invention concerns a conditional access data decrypting system, in particular for use in pay digital television broadcast. Said system comprises a broadcasting center (1) designed to broadcast encrypted data by control words (cw), at least one management center (11) designed to broadcast personal messages (ECM, EMM) concerning access rights to the encrypted data and to manage said access rights, an operating device (12) for making said encrypted data usable, and a decoder (13) for decrypting at least part of the encrypted data. Said decoder is located between the broadcasting center (10) and the operating device (12). Said decoder (13) consists of a module for receiving (14) the encrypted data and a module for managing (15) access rights to said data. The reception module (14) is connected to or integral with the operating device (12) and the management module (15) is designed to communicate with the reception module. The management module (15) comprises a security module (16) designed to verify the content of the personal messages (ECM, EMM) and to allow or prevent decryption of the control words (cw) on the basis of the personal messages. The reception module receives the encrypted data from the broadcasting center (10) and the management module receives the enabling messages (EMM) from the management center (11).