CA SYSTEM FOR BROADCAST DTV USING MULTIPLE KEYS FOR DIFFERENT SERVICE PROVIDERS AND SERVICE AREAS

摘要

A method for managing access to scrambled broadcast or transmitted events received from a variety of service providers (including broadcast televison networks, cable television networks, digital satellite systems). In one preferred embodiment, each service provider employs a different public key for encrypting the access information message, and each smart card includes the corresponding private keys for the public keys, thereby permitting a user to access events form various service providers without changing the smart card.