Enforcing software independent content protection in an electronic device during transcoding

摘要

A Set Top Box (STB) or client computer includes a communication interface operable to receive digital messages and digital content, memory, a transcoder, a central processing unit, and security processing circuitry. The security processor (or other components of the STB) is operable to identify protected digital content of the digital content that is to be isolated from the central processing unit during transcoding and to isolate the protected digital content from the central processing unit during the transcoding. The CPU may be denied access to a protected portion of the memory during the transcoding in which the transcoder stores non-scrambled protected digital content. The protected portion of the memory may be buffer memory accessible by the transcoder and not accessible by the central processing unit. The protected digital content may be identified from the digital message.