Stream generation method, broadcast receiving apparatus, and display method

摘要

Provided is a system far receiving a initialization packet containing an initial vector for initializing stream encryption algorithm and an identifier of a key for decrypting an encrypted stream, initializing a decryption module, and decrypting the encrypted stream, wherein the system stores an identifier of a key which is needed to decrypt a next program in a initialization packet of a current program and informs a user of whether a desired key has been acquired or not at timing close to start time of the next program.