Abstract: A broadcast data stream that contains a stream of encrypted data and a stream of messages. Data in successive segments of the stream of encrypted data is decryptable with successive decryption information from the messages. The stream of encrypted data is stored upon reception. The items with decryption information for the encrypted data are stored independently retrievable from the stream. Additionally synchronization information is generated and stored to link respective points in the stored stream of encrypted data to respective ones of the items with decryption information. During replay of a stored part of the stream of encrypted data the items with decryption information for the points in said stored part are retrieved. The retrieved items with decryption information are combined with the stream during replay at times selected under control of the synchronization information.

Abstract: A decoder decrypts data from the stream of data, using decryption control words. A secure device is coupled to the decoder to supply the control words. The secure device has a memory space for storing at least two items of entitlement information with associated authorization keys. The secure device has an input for receiving messages from the apparatus. The message contains information for example about the source of the stream. The secure device contains an execution unit that responds to the messages by selecting from among die at least two items, if stored, dependent on a content of the messages. The execution unit enables sending of the control words to the decoder subject to the presence and validity of the selected one of the items of entitlement information, after decryption of the control word with a decryption key associated with the selected one of the items.

Abstract: A signal (24) that contains a stream of encrypted data and a plurality of individually identified streams (20, 22) of messages. Each of the streams (20, 22) of messages contains decryption information for decrypting a common part of the encrypted data. In a receiving and recording apparatus a mode selection unit (16) selects an operating mode from a plurality of modes including a live rendering mode and a replay mode for rendering the signal with a rendering unit (14) when received live and when replayed from storage respectively. A decoder (14) decrypts the encrypted data using a selectable one of the streams of messages. The decoder (14) selects the stream of messages dependent on the selected operating mode.