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.

主权项

1. An apparatus comprising:
a communication interface configured to receive a digital message and digital content; memory configured to store the digital message and the digital content; a transcoder coupled to the memory, the transcoder configured to perform transcoding of the digital content, the transcoding including operations involving the digital content in a non-scrambled format; a central processing unit coupled to the communication interface, to the memory, and to the transcoder; and a security processing circuitry coupled to the communication interface, to the memory, and to the transcoder, the security processing circuitry configured to:
extract a rights portion from the digital message;decrypt the rights portion;based upon the decrypted rights portion, identify protected digital content of the digital content that is to be isolated from the central processing unit during transcoding by the transcoder; andisolate non-scrambled protected digital content from the central processing unit disposed within the apparatus during the transcoding of the protected digital content by the transcoder.