Back in December an enterprising programmer extracted volume keys from HD DVD discs; now, a processing key may break copy protection on all high-def discs issued to date.
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?
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RSSUntil this is resolved, or DRM is put in history's trashcan of poorly conceived technologies, cracking will be supported by mainstream users in self defense of their media investments.
While there is no doubt some truth to this, it's also true that there are legitimate reasons for cracking the encryption.
In my case my new HP system, sold as an HD-DVD media center complete with one movie in HD-DVD format, does not play HD-DVDs. Apparently the monitor it came with does not support the HDCP content protection.
To watch a movie in high definition, I'll have to bypass the encryption. If I can't play my paid-for movie because they sold it to me "defective by design", then I have no qualms about bypassing the defect.
Another reason is, as you say, to make a backup. High-definition movies sell for two or three times the price of older DVDs. You don't need to buy many before you have a significant investment - one that insurance companies won't cover. An off-site backup is simple common sense.
Another reason is for protection againt encryption key revokation. Bypassing AACS was reportedly much easier than cracking the encryption on the old DVDs. The AACS people knew that it was only a matter of time - why else include the ability to revoke keys for specific players and movies? With the very real possibility of my player or movies being reduced to scrap in response to a crack, I need the ability to remove the encryption altogether.
If this seems self-serving for the hackers, well, tough. I haven't pirated any HD movies and I don't plan to, but key revokation is still a real threat.
Finally, another reason is to protect against the format being made obsolete. Should HD-DVD disappear in favor of Blu-Ray (or a third format), I need the ability to transfer my paid-for movies to that format.