HD DVD's AACS Protection Bypassed

Mr. BS writes "Playfuls.com is running a story how HD DVD's AACS protection has been compromised. Although the video of the hack leaves much to be desired, the source code has already been made available. Feel free to start backing up your HD DVD's whenever you feel the need."

Comments

Dupe

[rrohbeck]

http://hardware.slashdot.org/article.pl?sid=06/12/ 28/0259244

And the winner is..

[Anonymous Coward]

I guess HD DVD just won the war against blu-ray!

The source is not for the "break"

[plover]

The source code provided is simply code to decrypt the stream. It's an implementation of the AACS published standard for decrypting a stream. What it does not do is provide a way to extract the keys from the disks.

The author is waiting till some time in the new year to reveal how he got the keys, but the evidence suggests to me that he used some kind of debugging hook into Power HD-DVD.

Re:The source is not for the "break"

[Gyorg_Lavode]

Pretty simple. He identified the encrypted key. He probably debugged the player and looked for routines that accessed that part of thefile. When he found them he ran the routine and pulled it's output out of memory.

It needs a name...

[jakedata]

How about AACS-Hole?

Should read:

[Swimport]

Feel free to back up your hd-dvds once you get some.

To be honest, I've missed the dupes

[Anonymous Coward]

When you have Alzheimer's, dupes are fantastic!

Par for the course

[fireproofjew]

Every encryption/DRM scheme that the companies think up will inevitably be cracked/hacked. All they need to do is realize that and then they can save money instead of pursuing a futile effort. I, for one, would buy the stuff if it was worth the money they charge.

Maybe they could charge less if they didn't take the time or spend the money developing newer DRM?

Re:Par for the course

[arminw]

.....Maybe they could charge less if they didn't take the time or spend the money developing newer DRM........

Maybe the movie and music moguls are duped by the inventors and purveyors of these harebrained copy protection schemes. The latter KNOW that the laws of physics and mathematics GUARANTEE that *any* copy protection scheme WILL be broken. After all, in order to use the content, the key has to be given to the consumer in order to play it. There is NO way to hide a key, if it is needful to be able to use it at some point in order to view the movie or play the music. Perhaps some sane crypto expert can convince the content producers that they have been lied to by these crooked, money grabbing "experts" who know deep down that none of their schemes can ever work for long. The hollywood and the music industry have been sold the equivalent of a certain bridge labeled DRM by these companies who make money selling their DRM schemes to the content producers. Content makers would likely make more money if they did NOT pay these liars a dime.

Hello? Article submitter?

[Jugalator]

Feel free to start backing up your HD DVD's whenever you feel the need

Not only do we skip RTFA quite often, the article submitters seem to as well.

What he says in that quote is simply not possible; you still need the keys, and that hack doesn't cover that problem.

We may have something for that too in the future, but this is not the hack for piracy-at-will.

Hey MPAA/RIAA cretins!

[kimvette]

Now that it's cracked, I might consider buying your media in HD-DVD and Blu-Ray formats, since now I can take care of Fair Use when it comes to format shifting and making backups. Until it was cracked there was absolutely ZERO possibility that I would ever consider purchasing HD-DVD and Blu-Ray media.

Don't you think it's high time that you quit trying to block Fair Use now, especially since the real pirates in China are totally unaffected by DRM in the first place?

Thanks for listening.

Signed,
A paying customer

Actually...

[raehl]

This was just a backup of the last article.

HD-DVD is -NOT- cracked

[derrickh]

Unlike DVDs, HD-DVD's have dual keys, 1 for the title, and 1 for the player. At the most, this guy has managed to make 3 titles playable on a single player. What will happen next is Cyberlink will have it's PowerDVD keys revoked and new keys will be provided with a patch.

So at most, you'll be able to 'back up' (or Pirate) the current batch of Full Metal Jacket HD-DVD's to play on an older version of PowerDVD.

So dont go around yelling about how HD-DVD is cracked, cuz it's not.

Here's an article that has a few more facts and less sensationalism.
http://videobusiness.com/article/CA6403011.html

D

Re:HD-DVD is -NOT- cracked

[DamnStupidElf]

Unlike DVDs, HD-DVD's have dual keys, 1 for the title, and 1 for the player. At the most, this guy has managed to make 3 titles playable on a single player. What will happen next is Cyberlink will have it's PowerDVD keys revoked and new keys will be provided with a patch.

And when PowerDVD is re-released it will have to load its brand new decryption key into memory and use it to decrypt the data from the disk. If they're smart-asses, they'll only use the decryption key for key setup or even completely skip the AES 128 key and directly build the AES decryption key schedule by some other obfuscated process. If they really want to get wild, they'll continually decrypt and reencrypt the key schedule so that its never fully intact in memory at any given point in time, and integrate the last decryption steps into the first huffman decoding steps for the mpeg process (since it's just a bunch of XORs) to further annoy crackers. Unfortunately, the fact that unencrypted material ever exists in PowerDVD proves that they must have the entire AES decryption key schedule available for any given decryption, and it will be relatively trivial for crackers to pull the key schedule out and just pick the first 128 (or 192 or 256) bits of the key schedule which is the original AES key. Trying to hide encryption keys within an executable's memory space is probably one of the silliest ever conceived. All an attacker has to do is try every K-bit (K is the size of the key) sequence of memory as a test key at several points in the program. That is in fact what this article's attack accomplished. The key schedule can be dynamically encrypted and decrypted as each word is required, but this is just a stopgap measure and slows encryption down significantly.

Re:Dance Dance Revocation

[Workaphobia]

This point has been mentioned a lot in this article's comments and the last one on this topic, but I'll karma whore and reiterate it:

There's a difference between the title key and the player key. The title keys are used to directly decrypt the contents of the dvd (or hddvd or blu-ray), and differ between discs. They are not revoked because they are never reused to begin with. The player key is what's licensed to the companies and stored in players. This is the key that allows access to the title key, and if compromised, this key can be revoked by simply not allowing it to decode any more title keys on future discs. So if this guy has obtained a player key, he can continue to decrypt future title keys up until the powers that be catch on, which may never happen if he doesn't publish it.

But he may not even have a player key. He might have just read the title keys, after they were decrypted by powerdvd, out of memory. I think that's what the GP meant.

I heard a suggestion in another thread that the title keys alone might be useful enough - the idea was that they could be exchanged freely across a p2p network, but the player keys that yielded them would remain in private hands to ensure their usefulness. I think the people discussing that missed one important point (although I could be wrong): the title keys should be unique not just to each movie, but to each disc containing that movie, as they are derived from the serial number in the disc. So your title key is useless to anyone else. It's a shame if that's true.

Guess the only thing to do is go back to trading gigabytes of movie data over bittorrent illegally, instead of a couple kilobytes of key data so you can view a legal copy. ;)