Back in December, an enterprising programmer found a way to extract volume keys from HD DVD movies, and even the AACS backhandedly confirmed its system had been compromised. Since then, volume keys to roughly 100 HD DVD discs (and even a handful of Blu-ray titles) have become de facto public knowledge and enthusiasts opposed to DRM make “backup copies” of their high-definition media.
Now, word is trickling out from the Doom9 forum that another brave computer enthusiast has cracked a process key on HD DVD discs, potentially compromising the AACS copy protection on all HD DVD and possibly Blu-ray discs distributed to date. What’s more, the attack comes not from reverse engineering software, altering binaries, or slicing into compiled applications with debugger software. Instead, the process key was located using good old-fashioned memory snapshots: the author of the purported hack simply studied the AACS technology white papers, then took snapshots of his system’s memory while playback of an HD DVD title began playing, noting what data in memory was changing. Eventually, what appears to be an unencrypted process key appeared.
My understanding of the AACS technology (confirmed quickly though not absolutely by industry sources) is that the AACS can in theory revoke the compromised process key, meaning that future HD DVD and Blu-ray discs would not be copyable using the new information. But so long as the savvy anti-DRM crowd can keep circumventing AACS protection every few weeks, one has to believe the technology will face significant pressure from industry and copyright holders. Is it possible the format war between HD DVD and Blu-ray will be called off because the industry believes both formats need more formidable forms of copy protection?
