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AACS Specifications Released
An anonymous reader writes "AACS, the proposed key management scheme for HD DVD, has finally released preliminary (ver 0.9) specifications. The specs look like CSS on steroids: they use AES instead of proprietary crypto, but other than that they're basically the same. The main difference appears to be that AACS can revoke an entire player model if a hack appears against it, which I guess sucks if you own that kind of player."
The main difference appears to be that AACS can revoke an entire player model if a hack appears against it
In that case, why would any manufacturer in their right mind produce anything under such terms? That would just be insane
The revolution will not be televised. It won't be on a friggin blog either
Click here to get the specification without agreeing to the terms of access.
"The main difference appears to be that AACS can revoke an entire player model if a hack appears against it, which I guess sucks if you own that kind of player."
Player model? What if a hack comes out for PC that allows you to circumvent the copy protection: Does it revoke PCs altogether, only certain disk drives, or what?
Creative Demolition
>> These documents are preliminary drafts and are subject to change without notice. To download the v0.90 specifications, please accept the above terms and conditions.
/.
No Thanks. I'll just wait for it to get posted to
http://request-header.info
This scheme will not be broken for at least 20 years.
There's no way they'll make the same mistake twice. DirecTV upgraded all their smart cards 2 or 3 years ago and it has yet to be broken. Bell Canada's expressvu is adopting the same technology because _everybody_ and their mom is pirating the signals.
You have your work cut out for you!
Just kidding. :)
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Now, how does this scale, suppose players AAA through ZZZ have been revoked. Do we need larger DVD cases just so we can fit a list of all the players that won't work on it?
THis new standard will probably require 15 lines
Snowden and Manning are heroes.
Well, what happens to the customers that have a player-model that gets, by no fault of themselves, revoked. Are they reembursed (getting (part of) their money back), or are they just left with a piece of worthless, but costly junk ?
Even worse : you have no way of knowing if the player you are going to buy is on the list of players shortly-to-be-revoked, or worse yet : allready revoked.
How's the "you should be able to use a bought commodity for a reasonable time"-law come in play here ?
Go Blu-Ray!
Albuquerque PC
It may be the strongest encoding out there, but who cares? What stops me from plugging the video output of a dvd player into my video capture card and recording off of it? Sure, the quality won't be as good, but it will still work.
I wish they simply wouldn't scramble content in the first place. 99.9% of the people who buy the dvd and would need to break the encoding have a LEGITIMATE reason to break said encoding (backup, copying to laptop so it's not necessary to carry discs on trips, etc).
In many countries (such as will probably be with Canada soon), there will be laws stating that bypassing DPM's (digital protection measures) is allowed, and legal, if it is of legal intent. SUch as fair use, backing it up, etc.
So, if you use it fairly in a country where its legal to do so, and they "block you", is that legal too? Is their EULA more powerfull than non-American laws?
Content Scrambling System = CSS.
AACS= Advanced Access Content System.
Maybe I am an idiot but i had to actually read the article to know what the posted article was talking about.
drop big bucks on equipment hoping someone does happen on a hack? Yea right and they wonder why only the sheeple fall for this shit.
Si vis pacem, para bellum! For evil to succeed good men need only do nothing!
If they can revoke keys, then we can DoS the keyspace. There's no need to crack any crypto. All we gotta do is trick them into deprecating keys.
How many people are still running windows 98? How many people know how to set the clock on their vcr?
You DoS the keyspace eventually people won't be able to play commercials. Then the productions don't get their money. Then the system does either of 2 things. 1: every screen goes black and there is no tv or 2: they give up and take off the crypto so the ads work again.
Key revocation is a bigger security risk than keys in software dvd players because you can do more than opening up a file to everybody. You can lock everybody out of it as well.
This idea (starting with hdcp I guess) just opens up more vectors for attack. Now we have a social engineering vector and a keyspace vector in additon to a locally stored key vector (css).
In that case isn't the cat already out of the bag? Not like they can on the fly say that all your HD-DVDs won't work in the morning... The only thing that they can do is prevent future media from playing on that model of HD-DVD player.
We have seen that play before, cripple the next hot DVD to hit the market and what do you get? A ton of product returns and pissed off customers. The encryption may be more advanced, but when you want to give everyone consumer devices with the universal key to the castle... It's only a matter of time before someone figures out a way to copy it.
Here's analysis of AACS that was blogged last December. One interesting point mentioned is that there is no requirement to wait for keys to get compromized before revocation begins. They can revoke keys whenever they want, publicly claim it was due to hackers, and stimulate new equipment sales any time they want.
Consumers' best interests would be best served my using NO crypto. All that crypto hardware/software costs money to develop and manufacture. Guess who pays for it in the end?
Then DVDs will die.
Most people won't even know what you are talking about.
Now having new DVDs automatically update the firmware is easy, stealthy, evil, and effective. I think some DRM systems use such an idea.
The user merely watches a movie, and their player gets reflashed in the process. That could work.
Expecting the average movie watcher to even know what to do with a USB cable and how to boot something off an external drive won't.
Just because it CAN be done, doesn't mean it should!
Seems to me that a manufacturer could sabotage another manufacturer's products by hacking them (under cover, of course) while they're still available new. That would make the players almost impossible to sell.
Aaah, now I see their dastardly plot... in order to avoid this, manufacturers will be forced to make their products hack-proof. Tricky, eh?
Remember Apple IIe games that wrote bad sectors or extra sectors and other such nasties to try and stop people copying 5-1/4 inch floppies?
Remember SecureROM and others making CD copy protection by intentionally leaving broken sectors on CDs - making them unburnable in nearly all of the burners at that time?
Remember that DVD's were once uncopyable?
Remember when Pay TV signals were encrypted by obfuscating their signal with some analogue hardware?
Remember when they started using proprietary digital encryption for Pay TV (Irdeto)?
Every time someone offers up content in some protected form, someone is going to break it. Period. Even if they can't break it, someone will use a legitimate DVD player and screen/sound grab their favorite movies using a capture card.
The only difference I see now is that the companies implementing these measures are monopolies whereas they used to smaller players in their respective markets. This might mean that they can push some legislation through to discourage copying but nothing will ever stop it IMHO.
Keeping on doing the same thing, and expecting a different result.
The Aussi-Gringo FTA fucked allot of things for the Aussi's (though they thankfully avoided the worst on their government prescription drugs program). From what I saw and heard, the FTA has little to nothing in it for Aussi's (loss of domestic TV programs, lingering threats to their PBS, etc). And the DCMA-esque copyright "equivalents" required by the FTA are headed their way (if not already implemented, life +70 years anyone?). The FTA is the only reason Australia has troops on the ground in Iraq, because the misguided "head jerks" wanted that fucking thing so damned bad for whatever reason ("Oh, oh, we can mitigate problems between the US and China because of our relationships with the two countries!" - so what? When two elephants dance, all you can do is get the hell out of the way).
"1984" was ment to be a warning, not a guidebook. You hear that Kim Jong-il!? BushCo?!
well i guess it's back to the old school - telecini a projection of the dvd onto an HD recorder. if it can be seen and heard, it can be copied. and one open copy is enough.
I used to have a better sig than this, but I got tired of it
to piss of sony, after all they are part of the consortium , ahhaahahahha
Liberty freedom are no1, not dicks in suits.
So I have a popular player. Someone hacks it. They revoke the key. I buy a new DVD. It doesn't play. I return it to the shop as faulty - it is clearly a faulty disc as my player plays all other discs fine. This bounces back on the producers as retailers don't want the hassle - I can't see them wanting to deal with the flood of customer returns.
Trading standards [insert the name of your country's equivalent consumer protection agency] could take the view that the retailer is knowingly selling faulty goods. The retailer would just refuse to stock any revoked discs in future.
I think the risks of revoking keys are just too great for them to actually do.
If they were dumb enough to do it, I can see huge global hacking effort to compromise as many players as possible, which would make the scheme unworkable.
If a major player maker's keys are revoked, they could easily appease customers by slipping them a firmware upgrade with alternate keys - maybe in the guise of a firmware disc intended for a new model that 'just happens' to also work on the older units.
Just think about it: to which extend can you abuse consumers? To the point where they discover they don't like the product.
At that point the bottom will fall out of the market.
Proof: see what DVD players sell best: those with zone restrictions or those without. The irony is that that does not happen because of piracy (pirated DVD appear to be generally set to zone 0 so zone selection is irrelevant) but because of legitimate purchases made elsewhere in the world.
So, in summary, let them progress down this route. Eventually the market will die as alternatives pick up the revenue.
As an example: how many of you buy protected contents or media in non-Open formats?
I have looked at pirated DVDs and they are indeed not worth the money - if you're in a country with sane media prices. If they really, really, really wanted to address piracy all they need to do is become more sensible with the prices, that has already proved to work (hello MS, are you listening?). The increase in revenue more than offsets the expenditure they have to put in on lobbying, researching formats that don't work or get broken in a rainy weekend by a couple of bored teenagers.
Hell, it'll probably even keep them in cocaine and limos.
Insert
They don't care about piracy. This isn't, and never has been, about piracy.
What they care about is control.
They care about linux distributions adding support to play HD-DVD movies, but not paying license fees to the DVD forum.
They care about HD-DVD players cropping up that allow you to fast-forward past the trailers at the beginning of the movie, the ones where a licensed player, when you say "fast forward", says "no".
They care about people making players behind their back which openly flaunt the "region locking" mechanisms that make regional price discrimination possible.
They care about products like DVDXCopy which allow consumers to exercise their fair use rights and do God knows what with the products they purchase.
These are the things they're trying to stop or hinder. Their choice of technology simply reflects that. AACS will do little in the short run and nothing in the long run to prevent piracy. But the legal barriers the media companies paid to erect will allow AACS to keep all four of the above things off of the general commercial market.
Irritable, left-wing and possibly humorous bumper stickers and t-shirts
Page 24: Each compliant device is given a set of secret Device keys when manufactured. ...The set of device keys may either be unique per device, or used commonly by multiple devices. ...The [Media Key Block] system is based on a large master tree of keys, with each set of Device Keys being associated with a leaf node of the tree... Further, corresponding to every sub-tree in the master tree is another set of system keys... Thus, the subset-difference tree has to store one encryption per Device Key set revoked, and occasionally additional encryptions to pick up non-revoked sets not covered by the smaller sub-trees. On average, there are 1.28 enrcryptions per revocation.
The document goes on to mention around pages 27 and 28 that devices obtain key conversion data by mechanisms called out in the AACS liscense, and recording devices must verify the signature and determine by its version number field whether a Media Key Block is more recent than the one currently on the media. "Each time the AACS LA changes the revocation, it increments the version number and inserts the new value in subsequent Media Key Blocks."
This says to me that the DVDs you buy will in fact be the transport mechanism for updated revocation keys, and presumably your player will be able to store a lot of them. So movie production companies and distributors must conspire to continually subvert the functionality of a consumer's device, and this does not require the player to be online nor will a firewall help. Once you get yourself locked into the prison of this coded delivery system, your own buying habits will keep adding additional chains to your cage. It is quite insidious, not only are they using military-level technology to control movies, the system is founded on the complicity of the entertainment industry, the electronics industry, and consumers themselves (and the consumer's PC if used) with constant policing and injection of targeted death-messages into the distribution channel. It also looks like the drive can potentially disable media (page 41) and even report hacked hosts/drives by recording onto the media (it seems kind of vague but it is writing a concatenation of the "Binding_Nonce", "Drive_Nonce" and "Host_Nonce" to the protected data area, whatever these things are), which if this is indeed true would I suppose be reported through other PCs/drives of people to whom you lend the media, or maybe through even a shared Internet connection, if you want to try extrapolating this.
Sorry I got ahead of myself. Page 55 talks a lot about online connections, online enabled content and streamed content. It talks about Title Keys and says "the word 'title' is often overloaded. For example a title can refer to a full-feature movie, a TV program, a music album, etc. ... however [we] .. define Title to be a distinct path.. That is, a Title is a logical grouping of content material to be presented in a specific order in time." It also mentions an "Enhanced Device" that is online and can then provide full access to Enhanced Titles that require online connections or extended player functionality. Page 56 mentions a Cacheable Permission that expires after a certain amount of time or include a "do not play until" date, and the XML based Title Usage File is based on global, not local time, which if used must be based on a "secure clock" whatever that is. Oh yeah, on page 59 it mentions the default connection protocol can operate (by https) over Ethernet, firewire, WLAN, etc. so you know this is not just about an HD DVD format but looks like it is trying to take over every device in the vicinity as well. How much you want to bet this will police titles not actually loaded in the player?
I think the cutest part is page 61, where it shows how you can go online with a PIN number and a remote Clearing House server can offer a title
Find the EEPROM chip which houses the firmware, copy data off it into an EPROM of similar size and install in the original chip's socket.
(EEPROM can be electrically erased, EPROM can't be reflashed by software). This depends on the ROM chip being a standard type rather than custom. Otherwise we're down to third-party modchips.
I have been a user for about 10 years. This ends Feb 2014. The site's been ruined. I'm off. Dice, FU
There must be decoded framebuffer somewhere to be blitted (and which can be memcpy to somewhere else, frame by frame). This can be then converted and repacked from raw. If going hardcore, then stepping some dvd player in debugger. Same goes for sound. I guess we won't see computer implementation of the thing.
With that in mind, it's clear that you can read what you quoted in the above sense, and indeed it's the plausible way to read it: it's not "causes a compromised device to be unable...", it's "causes a device with the compromised set of Device Keys to be unable...". Any device using this set of keys--whether it's superDeCSS or any particular machine of the sort that was compromised, or any other machine that shares the same set of keys--will no longer be able to view content--presumably only new content created after the revocation.
To me, this seems to be a golden opprotunity for organized crime, assuming they hire hackers good enough to reverse engineer a particular DVD player.
For example, say Sony make a really popular player, so organized crime get the AACS code hacked and then turn around and extort Sony - give us a lot of money or we'll release the key. If they release the key and this device blocking kicks in, Sony are going to have a lot of angry custumers demanding their money back.
At some point, somewhere, the entire internet will be found to be illegal.
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Here is why using a stronger crypto or longer keys is not always the answer. The design of the system around it matters too.
)9TSS
I can't imagine hardware vendors would accept that kind of technology abuse. In almost all European countries there is legally enforcable 2 years warranty for hardware products. Even if non-Europe manufacturer provides less time for warranty, retailer shop must comply with full time period.
So, that would be a legal massacre of retailers/vendors/manufacturers by consumers/consumers organisations.
There you are, staring at me again.
An open source DRM system could not possibly work. DRM systems work entirely on the basis that the decryption system is a black box - or at the very least that the user has no way to access the key. If the user could decrypt the stream and output it to disk, then the DRM has failed. To make matters worse, only one user in the entire world needs to be able to do this for the DRM to have failed, since they can then distribute their copy to everyone else.
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Also, contrary to what you may have heard, Blu-Ray discs will not require a cartridge. Blu-Ray discs should be more scratch-resistant than even current CDs and DVDs.
And about capacity: HD-DVD can only hold 30GB(15GB per layer), but Blu-Ray can hold 54GB(27GB per layer). In the future, Blu-Ray discs could even hold up to 200GB.
Albuquerque PC
The monopoly given to content owners to determine what others can do with content is subject to some "fair-use" caveats.
Isn't it about time that we, the people who are paying for this content get our fair use rights looked after. Anyone putting DRM controls in place should have a legal obligation to ensure that if if a customer has paid for the right to have access to the content that they also get their fair use rights as well.
It seems to me that the sorts of controlling technologies that are being envisaged here do not safeguard those rights. Isn't it about time we pressurised our democratic representives to ensure that we don't lose them?
Or just clip off the write enable pin on the EEPROM and ground it (or pull it high depending on the logic).
9/11 Eyewitnesses to Explosive WTC Demolition 1 of 2
They can use all the open crypto methods they want, that does not hide the fact that the flawed concept that is DRM depends completely on security by obscurity. It is not the crypto, it is the fact that you have to give the user the private key to unlock the data (because it has to reside on his machine) but you want to keep it hidden from him so that he cannot use it to decrypt the data at will. Someone WILL eventually find the key and extract it. If not from the hardware then from a software based player.
Finkployd
Think about it. For most people, their first DVD player is their *last* DVD player. Which is only replaced if something wears out or breaks. Now, with this nifty key-expiring system, the DVDCCA can "break" DVD player's by edict.
What better way to keep people purchasing hardware than to force obsolescence?
I think hacking the revocation keys could be more interesting.
A: Dude, I got this great new movie, wanna see it?
B: Yeah!
[A puts in an HD-DVD-R with all major revoke keys on it]
A: Oh shit, its not working man.
[A enjoys the little prank he played on B who will never be able to watch a movie again on his player...]
The previous sig has been removed due to
In Australia it now is, we are not allowed to create any copy protection circumvention mechanisms. To all you Americans: thanks for nothing.
Last I checked US troops aren't marching house to house in Australia, or occupying the Australian parliament.
Blame your own gutless politicians for your own mess. I don't blame Aussies for Bush being in office, despite the fact that one right-wing Aussie happens to own FOX and had no small part in running the propoganda machine that conviced approximately 50% of the US voters to vote the moron back into office.
You're responsible for your own mess, and the sooner you take your own leaders to task for it, rather than blaming a foreign power, the sooner you'll get it fixed. The same goes for us, by the way. The sooner we start blaming our own leaders for the current mess, rather than boogeymen in caves and Al Q'aide, the sooner our mess here in the states will get sorted out.
I don't expect either country's population to do this anytime soon, however.
The Future of Human Evolution: Autonomy
I'm a cryptographer, posting belatedly. I don't know if anyone will see this or read it but I had to comment.
_ no_fig.pdf. I will describe an over-simplified version.
Almost all of the assumptions in this thread are wrong. The system does not work cryptographically in the way people imagine. The technology makes it possible to efficiently revoke INDIVIDUAL DEVICES, not entire model lines. Every device can have a unique key, even if there are millions of them. There is no necessity or desire to make people's non-hacked players stop working. As others have pointed out, this would be INSANE. That's not how it works!
Cryptographically, this system allows the data to be encrypted to any of millions or even billions of devices, using a very short encrypted key block. What happens is that if some of those (individual!) devices get revoked, the size of the key block increases. Amazingly, the size is dependent on how many devices get revoked, not on how many devices there are. If extracting keys from a device is complicated and expensive, and not too many need to get revoked over the lifetime of the system, it will be a success.
The cryptographic technique is described in a paper from Crypto 2001 called Revocation and Tracing Schemes for Stateless Receivers by Naor et al and is available from http://www.wisdom.weizmann.ac.il/~naor/PAPERS/2nl
Imagine creating a binary tree with enough leaf nodes to hold all of the devices (again, this is individual devices, not model lines). Each device is associated with a particular leaf node of the tree. Now we assign a random AES key to every node of the tree, leaf nodes and internal nodes.
At manufacture time, each device is given all of the keys corresponding to its branch of the tree; that is, the key for its leaf node, and the keys for the parent, grandparent, etc. of that node, all the way back to the root node of the tree. As long as the disk is encrypted to one of these keys, the device can play the disk. Note that even if there are a billion device nodes in the tree this is only about 30 keys that a device has to hold, which is trivial.
Now, to create a disk, initially it is encrypted to the root node of the tree. All devices have the key for that node so all devices can play it. The key block is very short. But now suppose that someone manages to extract the secret device keys in their device, they get published on the internet (as happened initially with DeCSS), and everyone is able to use them to decrypt HD-DVDs. (BTW this system is also being used for Blue-ray! Don't think that's going to be any different!) Now what do we do?
What happens is that new disks are no longer encrypted to the root key. Instead, we partition the tree into subtrees that include every leaf node except the one which got its keys published. Now we encrypt the disk data to the root nodes of those subtrees, rather than to the root node of the whole tree. This will allow every other device still to decrypt the data, but that one hacked device can no longer decrypt new disks. The size of the key block grows based on the number of hacked players.
This is an oversimplified version because the size of the key block is bigger than desired. The paper above shows a more complex system, which is actually being used, which makes the size of the key block linear in the number of hacked systems. Assuming that hacking them remains relatively difficult, this should be an effective and efficient content protection system.
Basically this is the same method being used in current satellite TV systems, and for the past few years it has been successful enough that satellite piracy in the U.S. at least is largely a thing of the past.