First AACS Blu-Ray/HD-DVD Key Revoked 254
Thomas Charron writes "An update posted for Intervideo WinDVD 8 confirms that it's AACS key has been possibly revoked. WinDVD 8 is the software which had its device key compromised, allowing unfettered access to Blu-Ray and HD-DVD content, resulting in HD movies being made available via many torrent sites online. This is possibly the first known key revocation which has taken place, and little is known of the actual process used for key revocation. According to the release, 'Please be aware that failure to apply the update will result in AACS-protected HD DVD and BD playback being disabled,' which pretty much confirms that the key revocation has already taken place for all newly released Blu-Ray and HD-DVD discs."
I don't completely get it. (Score:5, Interesting)
I don't completely understand what's going on here. And that's exactly my point. I don't want to understand. Does this breach disable any user's player until they update their hardware? Will some disks play and others not? (I'm kind of making this up, but I'm role-playing what most consumers are experiencing based on my limited anecdotal observations).
I don't want to know the ins and outs of the security of the media. I want it to work like the old CD players. I insert a disk, I watch a movie. Simple. Easy. Done.
I think above and beyond the hurdle of introducing a new format, ahem, two new formats, for DVDs this kind of hiccup could be fatal to the rollout. People are annoyed enough with little things (cables plugged in wrong way, audio/video receivers improperly configured, etc.), when it comes to having to update firmware to be able to play stuff they've paid for, they're going to be mad. And maybe some, maybe many are going to rethink their upgrade plans and find regular DVD okay enough. And maybe people who have been considering HD DVD will stay away in droves. Fingers crossed.
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Put simply: industry + clueless = idiots who damage their own profits. The music industry has proven this well already -- now it's time for the movie industry to not learn from the past.
Re:I don't completely get it. (Score:5, Informative)
This is why HD-DVD and Bluray players require a network jack. It allows for old keys to be removed and new ones to be implemented, among other things.
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Re:Network jack?? (Score:4, Informative)
Re:Network jack?? (Score:4, Informative)
Of course, this is not the case; there are likely other ways of updating firmware on "real" HD-DVD players, but they're likely to be less transparent to consumers.
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Instructions for continuing to be able to use your (friken expensive) player.
1) Use your computer to download the latest firmware.
2) Burn a CD/DVD (you sure as hell had better not need to burn a blu-ray or hd dvd disk!!)
3) Insert in you player and power cycle and hope the upgrade works and doesn't leave you with a brick.
4) Continue to pay a premium for content for your player knowing that you'll probably have to do this firmware shuffle at least twice a year.
or
D
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720x480 interlaced video.
1920x1080 progressive video.
A few more lines?
Suppose it'd be even easier for you just to go cower into a small hole and ONLY support pre Macrovision VHS.
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All HD DVD players have a network port (Score:4, Informative)
Blu-ray, however, has networking optional, and most Blu-ray players don't have a port.
Yet another way in which the baseline functionality in HD DVD is much higher than Blu-ray.
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Updates for hardware players unnecessary (Score:4, Informative)
None of that matters for hardware players, because each individual player can be revoked independently, without affecting the one that came off the line immediately before it, or the one that came right after it. They don't bother issuing unique keyset to each copy of a software player, for obvious reasons, but hardware players all have unique key sets so if the keys in one of them are compromised, and known to be compromised, then that specific player can be revoked so that future disks won't play on it. No updates to other players are required.
What makes this magic possible is a very clever and sophisticated key derivation scheme. Basically, there is an enormous tree of trees of possible keys, and each player is given a carefully-chosen subset of them, which allows that player to derive a large part of the possible keys, but not all of them. To revoke a key essentially just means choosing to encrypt future disks with a key that particular player cannot derive with keys.
The number of key blocks that must be placed on each disk to make this scheme work is linear in the number of revoked players. In fact, it can be shown mathematically that if r players have been revoked, then at most 2r+1 key blocks are required on each disk. Simulations show that assuming a random distribution of revocations, on average only 1.28r blocks are required. Each key block is 16 bytes in length, so they can revoke millions of players without significantly affecting the space available on the disk.
Re:Network jack?? (Score:4, Interesting)
This entire thread is complete bullshit. Keys are not revoked via a network jack. Keys are revoked by the simple act of releasing new discs that don't support them.
So this bit is pretty well established
1. Player gets compromised (keys extracted somehow)
2. All new content no longer has a key for the compromised player.
a. Your player cannot play these new disks
b. The new content cannot be decrypted by hackers either.
c. Anything currently released will still play fine.
Now the interesting bit is how to update the players. The key system on Blu-Ray is very clever, and allows enough keys that they will never run out, at least in practice. It was designed to allow revocation of multiple compromised players, hundreds of times over.
The real issue is that you don't want a legitimate player to stop working. A software player can easily be updated on the internet. But a hardware player cannot assume an internet connection. And consumers are going to get angry if their player stops working because someone somewhere managed to figure out its keys.
However, there is no reason why a firmware update for the hardware player cannot be included on all new titles released. There is plenty of space on a Blu-Ray disk to hold thousands of firmware patches, for every compromised hardware player. So the end users will get updated.
Which doesn't mean that a real hacker couldn't "upgrade" their program too, but its a world of difference between figuring out a single key and emulating the system through an upgrade.
However, the biggest reason for this system is that of forcing a delay.
If you stop keys being released for a few months you capture most of the sales market
Sure, you may lose the long tail of marketing, but if you can just keep the decryption keys out of circulation for a few months plenty enough people will buy the disks anyway.
And they can play this cat and mouse game for a long time to come....
My 2c worth,
Michael
Re:I don't completely get it. (Score:5, Informative)
Actually:
1. New discs won't play on the players who has had their keys revoked. Just to make that clear, this only has any effect for users of the WinDVD software player.
2. If I remember correctly, the player will keep a version of the revocation keys. So from what I've understood, once you put in a disc which says "Hey, you're supposed to be revoked" that player will stop working until you get an upgrade.
For a software player, this isn't more than what it just said - a required software update. It doesn't get nasty until hardware keys are found...
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Ouch. Imagine all the damage an enterprising anti-DRM vigilante can do if revocation lists can be faked. Or a SNAFU in the manufacturing plant.
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This myth appears to have originated simply by a reporter from The Register misunderstanding an out-of-context quote, from someone who didn't entirely understand AACS to begin with.
Reading about AACS from the source, I didn't see anything like this at all. So please stop spreading bullshit myths.
And don't drink coke while you're eating pop rocks, or your stomach will explode, and yo
Re:I don't completely get it. (Score:5, Informative)
It's not a myth at all. Try reading section 4.8 of the AACS Introduction and Common Cryptographic Elements [aacsla.com] spec:What this means is that disks are distributed with Host Revocation Lists on them, cryptographically signed by AACS. Whenever a disk is inserted, the drive checks to see if the HRL on the disk is newer than the one it has in nonvolatile memory, and if so, it checks the AACS signature on the new one and stores it in memory. This allows a drive to refuse to talk to a given host software. Likewise there is a drive revocation list that the hosts are supposed to hold which tells them not to talk to certain drive versions, in case an attack is found in some models of drives.
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Re:I don't completely get it. (Score:4, Interesting)
The net result of this is, once inserted, the disc guarantees that all future discs will play regardless of the player codes which have ever been, or will ever be, revoked. Since it has no concept of time except for the supposedly monotonically increasing version numbers of the HRL, it should be possible to max out the HRL value so no disc can ever update the player's revocation list.
I'd be suprised to find out that this is not possible.
Re:I don't completely get it. (Score:4, Informative)
Storing the revocation list like this is likely only useful so that the device can give the user specific instructions to go look for an update, and maybe disable itself even for older discs. Every new disc will still fail to provide a disc key to the player, as the player key will not be included in the tree of allowed ones. You still couldn't play new discs, the best you might do is prevent the player from understanding that it needs an upgrade.
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It isn't a myth, but Host Revocation and Drive Revocation are trivial to bypass and are not what is being described in this article.
HRLs and DRLs only serve to stop Hosts (PCs) and drives (HD-DVD or Blu-Ray) from communicating with ea
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The answer is neither....
When screw the customer is one of the FEATURES of a product the people selling it are #$#$%$% morons!
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You own the discs, no one is going to take them away from you. You own the right to use those discs. However WinDVD8 lost to right to play those discs. WinDVD8 then is issued a new key, and will continue to be allowed to play those discs. It's just requiring a update for the software. That seems reasonable in this case. Completely locking out a hardware drive or something that can't update would be unreasonable, but right now this isn't sounding like a
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Works for me.
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Fixed that for ya.
It's hard to upgrade hardware (Score:5, Insightful)
A hardware player isn't a general purpose computer. I'm sure it's possible for somebody with the right hardware to snoop inside its memory (say, inserting a special thingamabob between the memory and the mother board that allows you to read all reads/writes as they go past), but it's not going to be readily available.
Presumably somebody will be the first one to do this, and that is sure going to be a bad day for both formats. People are prepared to upgrade their software; it happens all the time and it's a relatively painless process for most people. Upgrading your hardware is not going to be easy, and it may not even be possible. (I used to own a DVD player which was "upgraded" by downloading a patch, burning it onto a CD, and putting that in the machine, but I don't know if every DVD player supports that.)
If they start denying keys on hardware players, there will be a world of pain, but I don't expect this to shatter the world. They'll just advise everybody to download a patch with a new key.
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Only if you try to get the key directly from the hardware player. I remember reading with DeCSS on the standard DVDs, that the keys were guessable by a human once they found a pattern in them. While they are using 128bit encryption for Blu-Ray and HD-DVD and DVD only used 40 bit, they still use multiple keys for unlocking the content, effectively reducing the number of bits by who knows how many. It's p
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It's simply unlikely. AES' 128 bits is too much, and the algorithm has been shown to be too secure at present. It's a highly critiqued algorithm that has been proven not highly vulerable to known techniques of cryptanalysis. AES has a highly mathematic structure
thingamabob = logic analyzer (Score:4, Interesting)
Re:thingamabob = logic analyzer (Score:4, Interesting)
You just made my day. I learned something new (Score:2)
I can imagine this being very difficult, especially if the crypto engine is a small part of a much larger chip (like, an FPGA or something).
Re:It's hard to upgrade hardware (Score:4, Interesting)
Actually, it is. Toshiba's first HD-DVD players are, in fact, Pentium 4 computers.
Not ALL, but the vast majority of DVD players can be flashed in the same manner.
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I don't have the link readily available, I think the actual paper may have been pulled from the web and thus only available on the wayback machine, but AACS has the ability to revoke individual players.
In a nutshell the way it works is that players do not have just a single
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Lets say the market is 580 million players.
580 million * 128 bits = 8.64267349 gigabytes
That is 8 gigabytes just for the keys. Let alone the amount of time required to try decoding each encrypted field.
Sorry, it just won't work.
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No, it doesn't. Mathematics isn't nearly that primitive. You absolutely don't have to, nor does AACS store every individual key on a disk. It's called "broadcast encryption" and it existed before AACS. Each player doesn't have a single, globally unique key. It has several keys which, in combination, are globally unique. See: http://web.archive.org/web/20060604054302/http://w ww.lotspiech.com/AACS/ [archive.org]
Sorry
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Awesome (Score:5, Funny)
Re:Awesome Monopoly Powers, Activate! (Score:3, Insightful)
But therein lies the problem with this situation. The **AA cartels have purchased the necessary legislation to reinforce their monopolies. When they revoke a DRM key that effectively bricks your hardware player for future media releases, what are you going to do? They've cost-shifted the upgrade burden onto you, and since they own the entire distribution chain, you can't take your business
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If only people would wake up (Score:3, Funny)
And the establishment will respond thus:
Yeah, that copy protection sure is painful, huh? Goddamn those freedom hating movie pirates for making us put it on there. You know those guys f
let's have a vote (Score:3, Informative)
Re:let's have a vote (Score:4, Insightful)
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I have only bought 3 un-cracked DRM'd media, I have plenty of DVD's but their cracked, so no worries they load up on my media player with just a couple clicks, and a hour later it'll be loaded on my player whenever it is next turned on.
odds are that what you meant as well, you purchase no DRM'd content that is still effective.
FYI, of those 3 I bought, 1 I never got anything to work (e-book), the other 2 I got video only, no sound (HD content on DV
And even more amazing (Score:2)
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Due to the ignorance of the average consumer, DRM products become widespread, and, within a few years, become a defacto standard. Now it's too late, both for the educat
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Case in point - Itunes. I used to use it because the Hymn project had a crack for the content. I could buy the music and decrypt it and use it however the hell I wanted. When they changed the Itunes scheme and Hymn no longer worked, I stopped buying Itunes. Problem so
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soo.... (Score:2, Insightful)
it's entirely possible that i have this all wrong.
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.. but what if a hardware player is compromised? (Score:3, Interesting)
i don't even know if this has happened with dvd or how possible it is.. but i have to think the potential is out there, and unless the unit has some sort of design foresight to resolve some issue (firmware updates to my bluRay player? and what kinda new 'security' hole is that?!?) i'd think you could be toast.
-r
Re:.. but what if a hardware player is compromised (Score:2)
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Re:.. but what if a hardware player is compromised (Score:2)
You'd be surprised, but AACS uses a pretty clever system for key revocation which can revoke a single key without having to change anything in players with a different set of keys.
The keys are nodes of a binary tree where the leaves are the individual keys per player. Each player has the keys
Re:.. but what if a hardware player is compromised (Score:2)
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Copyedit? (Score:4, Insightful)
Re:Copyedit? (Score:5, Insightful)
(World's easiest job: slashdot "editor.")
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hardware players? (Score:3, Interesting)
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None.
would [it] be possible to hack apart a hardware HDDVD/Bluray player and take its key?
Nobody's done it, but if it happened they coudl revoke that key. Of course, if you found a way to extract it from a class of players, they might have to recall all those players.
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Still I'd love to see the necessity.
Great! (Score:5, Insightful)
And we know how smart InterVideo have been about protecting the keys so far...
The fact of the matter is that if it can be decrypted and the user has physical access, there is *no way* to make "unbreakable" DRM. None. At all.
Especially on most modern CPU architectures where memory and the bus are unencrypted. The data *has* to go through RAM and over the bus.
Therefore there *is no protection*
It takes *one* decrypt to defeat their supposed purpose "keeping them dirty pirates from getting it" and this decrypt will *always* happen. But yet they waste millions in R+D money making ridiculously bad systems to try to prevent something that's physically impossible to prevent.
The Zero-day race is on (Score:2)
Re:Great! (Score:5, Interesting)
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They can try it if they want to face a class action from everyone who's bought an HDDVD drive for their PC. I still don't see that intentionally and specifically disabling somebody's property can be legal.
Microsoft might object to that! (Score:2)
I know that Microsoft has the Xbox 360 with the HD-DVD add-on drive, but surely they might have a bit of incentive to be in the "media centre" market where Vista is the focus of an HD home theatre? If there are only "hardware" solutions, they would be shut out. Could Microsoft afford that?
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Derek
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There's no way to make DRM unbreakable IN SOFTWARE. However, even there, there are numerous ways to make it so ridiculously difficult to find the key, that it would either require millions of dollars in equipment and thousands of man-hours for each key (which can be trivially revoked) or perhaps waiting many years until technology improves, until they don't really care anymore if the DRM is broken.
In hardware, however, DRM can be absolutely impossib
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The user still has to be able to *view* the content. There is no DRM for the mind (yet, hopefully ever).
No matter how much fancy full-pipeline encrypted hardware you build, the user still has to see it. And our minds don't support AES.
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Which is better? (Consider video but ignore sound.)
1) A DVD rip from filesharing networks.
2) The movie from an HD-DVD which has been projected onto a (HDCP) display, recorded with an HD camcorder on a tripod, compressed and uploaded to filesharing networks.
The DVD rip, of course. The movie studios, in this scenario, have wo
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Still not optimal, sure, and sure the studios have won a tiny victory, but it's still guaranteed to be better than SD.
Then there's the fact that to make a system "secure" up to that point requires integrating the crypt
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No. Everyone is quick to talk about pointing a video camera at a screen, but it's expensive to get HD equipment, works pretty badly in practice (eg. refresh rate, black level, etc.), and with the quality loss, you might be better off just copying the DVD version instead.
But additionally, a electronic eye sees things very differently than human eyes. There are numerous methods to make moving images look perfec
First AACS Blu-Ray/HD-DVD Key Revoked (Score:4, Insightful)
Ahh, certainty (Score:5, Funny)
Well, I'm glad that's been confirmed...
New use for PS3 Linux (Score:5, Funny)
Anybody remember... (Score:2)
As quick as the satellite broadcasters changed keys, the hackers would crack and distribute them.
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What happens when V9 is available? (Score:2)
right of first sale? (Score:2, Interesting)
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Since you are selling not original - but copy - no way it would classify as "first sale". IOW, private copies are reserved for private use - sale/rent/etc aren't private uses.
P.S. IANAL
Re:PS3 (Score:5, Insightful)
It would be more interesting to find out what would happen if the key to the Sony standalone BluRay players was discovered.
Yes, but... if it was hacked once.... (Score:2)
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They'd probably do what standalone DVD player vendors do - release a firmware update as a disc image that customers could download, burn, and insert into their standalone player. From there, it works much the same way as flashing a desktop computer's BIOS - the DVD player starts to load the disc, recognizes it as an update, and flashes its firmware. (For example, Pansonic has n
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But after a while it will become impossible to get updates for older models of players. People will have to keep on buying new ones as the keys for their old ones are revoked.
Perhaps the stores will start having special offers: "buy this disk for $100 and get a free player that will play it".
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Actually, this sounds like a great new business for "Geek Squad". We can rescue your player from those evil hackers - pay us.
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I imagine the PS3 has a 'hard to get' Private Key (or even multiple ones) on a hardened chip somewhere. So they encrypt the key during the upgrade (i.e. on the wire, and presumably store it encrypted in the firmware) with the public key, and the PS3 decrypts it with the private key on demand.
After all, if the key is currently sitting in the PS3 firmware already, unencrypted, how hard do you think it would be for people to crack the encryption without an upgrade happening?
(NB. I am not a cryptographer, I
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but a firmware update on disc is a MUCH easier thing to manipulate than the one on the player, that was one of the points I was trying to make
Yes, but my point was that it wasn't. Either you can decrypt the key or you can't. i.e. either you can attack the encryption algorithm or you can't. Unless I missed some breaking news, you can't. As I indicated, it's not like they'll be sending/storing the key in cleartext.
So the same methods that you mention (wait until the software has to decrypt the key(s), because it always does) will still work. I don't see that they'll be any easier, though. Now they're known, it's obviously quick to do, but
Re:PS3 (Score:4, Interesting)
Actually, it's very well-known what would happen: They would revoke the individual player that had its keys compromised. Note: Just that single unit, not the whole line. The beauty/horror (depending on your perspective) of the AACS key revocation system is that it can target individual units without affecting any other units, and it can do this without requiring huge amounts of disk space to be devoted to key blocks, and without requiring any of the devices to get updates, even if millions of individual players are revoked.
What this means is that smart hackers won't reveal the player keys they extract. Instead, they'll use those keys to compute the media keys, and then they'll publish the media keys. Your HD-DVD/Blu-Ray ripper will just have to consult an on-line database to find the key for the disk you have and then it will be able to decrypt it just fine. The media cartel won't be able to revoke the player key used to compute the media keys, because it won't know which ones they are.
Incorruptible projectionists? (Score:2)
Even if it's not part of their job description [careerplanner.com] to "install a camcorder where it can film the screen from above the heads of patrons and use a Y-cable to patch the sound directly to the camcorder", I can't imagine how anyone can pretend it's impossible for someone to arrange a special screening with the projectionist at one of the tens of thousands of movie theaters available worldwid