DRM is briefly mentioned. But no explanation for why TLS is necessary on top of that. Is the DRM crypto cracked? Or, as they hint to, are DRM keys the same for all users ("pre-encoded") and thus identifiable?
It is pre-encoded, with a unique stream key (like a session key). The stream key is then encrypted with the public key of each playback manufacturer (multiple copies of the key, one per manufacturer) in DVD CSS. A more complicated scheme is used for Bluray which provides for unique keys for each player but without significant overhead (see http://www.wisdom.weizmann.ac.il/~naor/PAPERS/2nl.html).
