From my understanding, you can create as much "DRM" code as you want, but you must provide the cryptographic key along with the source. This extends to the plat

From my understanding, you can create as much "DRM" code as you want, but you must provide the cryptographic key along with the source. This extends to the platform that the code runs on; for example, "Tivo" can't distribute a GPL3 binary in their set-top boxes, lock it down using a cryptographic signature, and fail to distribute the signing key. It would be impractical for the GPL to determine what counts as DRM and what does not; so they merely require "free modification of the Software".