DRM and output capturing

Most DRM circumvention discussions evolve around decryption. But wouldn't it be much easier to write a program that captures the output, after the DRM has done the decryption process?

For example, instead of using a program to remove the encryption of a DVD, one could write a program that captures the audio and video output signals when the DVD is played, and then assembles them into a new unencrypted file.

The advantages of such an approach are evident - the strength of the encryption employed by the DRM vendor becomes irrelevant, since the copying is done at a stage where the information is no longer encrypted. Further more, this approach will enable a "cross-DRM" circumvention tool. The same tool could be used to overcome any DRM system that runs on a PC. The tool could capture the output of any CD, DVD, or other encrypted file, regardless of the encryption system.

There might also be some legal advantages - the tool would be able to capture the output of any file, not just the output of encrypted files. As such, it could be used for non-circumvention purposes (e.g. changing the format of multimedia files, sampling, fair use copying of non-encrypted files...) and would not necessarily be regarded as a circumvention tool.

I would appreciate your thoughts on the issue.

Didi Melchior
http://mishpat.net
Mishpat Legal Information Received on Wed Apr 30 2003 - 22:43:48 GMT