Method and Circuit for Encrypting a Data Stream

摘要

Current legislation requires the possibility of encryption when storing television programmes received by broadcast. However, legacy playback apparatuses will not be able to play back such encrypted data in a regular way, but possibly in a wrong way. This may result in problems like damage of speakers. Therefore, the application intends to hide any of such possibly damaging streams by intentionally providing such streams with a wrong identification during the encryption process. The application provides among others a method and circuit for encryption and a method and circuit for decryption. The application is especially suitable for DVD recorders, but may also be employed for other video and/or audio recorders. The invention may even be used for encrypting non-audiovisual data.