HD-DVD and Blu-Ray AACS DRM Cracked?

"According to this article on Endgadget, the AACS DRM used in HD-DVD and Blu-Ray has been cracked. The program allows one to decrypt and dump the video for play on a users hard drive, or it can be burned to a blank HD-DVD and played on a stand-alone player. According to the accompanying video, a source release for the program will be made available in January. Time to get that $200 Xbox 360 HD-DVD drive?"

Article: AACS DRM cracked by BackupHDDVD tool? - Engadget
Source: Slashdot.org

[OT]
There is a video of the tool apparently decrypting the movie "full metal jacket" on windows, but i havn't seen any other proof that this works

Source Code available in January, thats the proof we need! does that mean it will be working on Linux in February I was wondering why this was done on windows.... but im guessing Linux HD-DVD support is non-existent due to the DRM.

To be honest, of course it's been cracked. If a movie is encrypted, then there has to be some way for the user to decrypt the movie so they can watch it... so once you have a copy of the decryption key and you know how the file format works, then surely there's nothing stopping you?
[/OT]

 

I have no experience in decrypting media content, but I suppose its possible to reverse engineer the decryption method from a stand alone player. Either that or do it from a software method.

 

The only suggestion for a bullet proof content protection scheme that would be near enough uncrackable I've ever seen was a little far fetched... it involved training the brain to decrypt what it was seeing on the screen with the aid of psychedelic drugs! this would be a right :swear: to reverse engineer, as the decryption occurs in your brain! (and so a decrypted copy never touches the computer / player)

not a great solution, as i doubt anyone has any clue where to even start making such a system.

From reading through the article AACS works like this:

Every player has its own unique public / private key, a copy of the key that will decrypt the movie is stored on the disc encrypted with all of the public keys. a player uses its private key to decrypt the movie-key stored on the disc (that was encrypted using its public key).

The biggest problem with this is, once you know the movie-key... you know the contents of all the public key encrypted movie-keys, which only the players private key can decrypt... but since you know the content of the file, you should be able to calculate the private key used!

so if you can obtain the movie-key, or one players private key (they both have to be on the computer somewhere) then you can get ALL the private keys!

 

That'd be...erm...weird to say the least!

Smack-head 1: "Duuuuuuuuude lets get mashed and watch some encrypted porno..."
Smack-head 2: "Encryp...tee...what?"
Smack-head 1: "Who are you? Where am I? What the..."
Smack-head 1: *looks at porn on screen*
Smack-head 1: "Oooooooo"
Smack-head 2: "Strange colours..."
Smack-head 1: "Here you need this..."
Smack-head 1: *Hands drugs to Smack-head 2*
Smack-head 2: "Oooooooooo, now I see..."

 

That is insane.

 

its getting better, assuming HD DVD/Blu Ray Players will refuse to play non-encrypted disc's making backups its going to to a PITA.

if AACS Relies on ANY read-only elements on a disc (such as the disc serial, manufacturer etc) then you will have to re-encrypt the ENTIRE movie on a per-disc basis. If so, there should be some interesting court battles in france (where i believe its legal to make copy's for close family members, dont quote me on that tho).

while this might stop me making disc's for my friends bob and fred, its not going to stop Mr Pirate who can afford the technology to just create discs that all have the same serial number!

this is good reading : http://www.securityevaluators.com/eval/spdc_aacs_2005.pdf

 

Hang on, i have the ultimate solution for making backups of your HD Movies! all though it will take the length of the movie to do, it will provide you with a perfect 1:1 decrypted copy and works with all content protection systems ever produced, and ever will be produced!

Record the Output from the dam hardware-based player! I am aware that there is some sort of protection from this attack (i remember connecting a DVD player up too a video recorder, it would only record for 3 seconds before it stopped) i also know that it can be stripped with a Man in the Middle style attack (a box between the player and recorder).

with the extra hardware, the recorder doesn't believe that the stream its recording is 'protected content'.

 

From a BDA Press Release:

On Blu-Ray at least this shouldn't be a big issue as one of the main features of their copy protection is the ability to shut down a specific player or line of players that have been compromised. They also added the ability to modify the code the players are running so they can change the keys on each player pretty much anytime they wish.

 

Do you think they will ever risk the wrath of 1000's of customers who find they can no longer use there :swear: expensive hd player to watch new movies? i seriously doubt it, unless there going to provide a new player to all the affected customers, which i also seriously doubt.

This is referring to hardware hd players, the sort that plug into TVs. While in theory they are just as exploitable, probably more so as i doubt manufacturers will have taken any steps to protect the private keys in the players memory, i doubt they will play a massive part in attacking AACS... at least until software based hd players have implemented protection features that make it harder to obtain there private keys than obtaining them from flash memory chips on hardware based players.

Client Side security is an flawed concept... its doesn't offer security's, it only offers protection for a limited amount of time.

 

Considering Fox was the main lobbying force for the inclusion of BD+ I can easily see them willing to shut out consumers to protect their copyrights.

As far as other studios you just have to remember how many people they alienated by deciding at first to implement Image Token Constraint before they finally decided to put it on hold for the time being but could implement it at any time. If they were willing to upset most HDTV owners who only have component in I can easily see them willing to upset customers who they feel are infringing on their rights.

 

I only just fully read the above posts (I was a little tired).

Isn't the point of public key encryption that it is mathematically difficult to obtain the private key used? If you say we could do that, wouldn't people capture network data from encrypted SSL connection, and then find the private key?

I doubt your doubt. Although CSS was terrible, don't you think manufacturers would realise the risks? Especially if one of the employees happen to have read your post

Aren't all types of security limited? The most secure vault in existence will still fall to the second law of thermodynamics eventually.

 

Apart from the fact you dont know the exact content of the traffic you've captured, then yes theoretically... but im basing this on a slashdot comment, which thinking about it i now have serious doubts about... (what would stop you calculating the private key by just encrypting anything with the public key?). Im not dismissing it entirely, as im sure it still takes quite awhile (but it should deff help reduce the amount of time taken).

If They have any sense, they will only store it unencrypted in CPU registers (it must be encrypted while traveling any accessible buses, or stored in any accessible memory... but the problem is, where do you store the decryption key for the AACS private key?

Client side secuirity even more so, you cannot stop a motivated, skilled user from copying or editing what is on there machine. it is simply impossible as they have physical access to machine, software and an unlimited number of attempts and time to do it in.

 

Well I was thinking that the private key is virtually impossible to decipher with current computational facilities when working with keys of high work factors. e.g. 2048bit keys.

I agree about the client side security, but providing the key storage device is isolated enough, and inaccessible to the user without destroying it, it should be safe to a certain extent. Possible within this, they could use a strong symmetric encryption algorithm like blowfish for an extra layer.

 

I reckon you could do it with a distributed system using rainbow tables (and ALOT of computers), where each machine calculates part of the rainbow table and reports the range of range of the keys it has calculated... this is just speculation, as i don't know how they keys are calculated (but i guess the public key is based on the private key, because the private key would logically be random).

I don't know how much processing power would be required, but i reckon the 'owners' of botnets might have a chance (again speculation, i will look all this up sometime soon).

 

I just tripped up on this for the first time today.
HD DVD copy protection circumvented?

Here is the start himself. If I found him no doubt other people can too.
BackupHDDVD, a tool to decrypt AACS protected movies - Doom9's Forum

 

It all depends on the size of the private key. Factoring extremely large numbers is computationally infeasible with no efficient algorithm known. Thus, even with a petaflop capable supercomputer, you would still have a hell of a time trying to crack 2048bit RSA.

 

I am not really sure what the kaffaffel is all about. :dry:
But.... if the industry is making it near impossible to backup your legal movies, surely it should offer the consumer some type of guarantee in case the movie does go wrong. If there was an accidental damage, you should be able to claim a new copy via your house content insurance.

I always found it a bit strange that people will go to such lengths to back up their precious DVD's. At the end of the day a DVD is just a DVD and cost £10-£20. It is not designer stuff, dotted with diamonds, is it? I can understand it but I still find it a bit strange.

How is the industry going to tell the difference between an honest consumer prizing his DVD collection and a bastard pirate copying the latest releases and selling them down the market?

 

Looks as though it's just an issue with PowerDVD Ultra so I'm sure this version of PowerDVD will be blacklisted soon enough. Just hopefully Cyberlink is going to provide free upgrades to anyone who buys their software.

 

Its Not only about backing up your movies, I like to have copy's of my DVD's on my computer so i can watch any of them without having to find the disc's (or even move!).

If I legally own a copy, as i have bought it, surely i can decide how i watch and store it?

[OT]
I am not using Microsoft windows, there wont be an official player for my operating system of choice, the only way i will be able to watch AACS dvd's in Kubuntu is when a) it has been cracked (without needing 3rd party windows software) or b) using windows software in a virtual machine running a copy of windows (Virtual machine = a computer emulating an entire computer, with an OS running on it!)
[/OT]

I Have never bought a Pirate DVD, i have never sold a pirate DVD and yet, i am treated as the pirate?

 

###This is by no means condoning or condemning piracy!!!!#####
I think you did not get to the bottom of my thoughts.
There are millions like you who are honest, decent consumer who are wiling to pay good money for a proper product.
The only way for the industry to protect its products from being pirated is by making it illegal to copy. But in order to enforce this, things have to be black and white. Backing up for personal use, even when you own a legit copy is a grey area...

I wasn't implying in any way that you are a pirate, but as far as the industry is concerned, there is nothing stopping you from making extra copies and then selling them on.

I am sure that if anyone ever dawn-raided your house, they will have a hard time convicting you of anything as you do not own a duplicator, have hundreds of blank DVD's lying about with the printer spewing front/back covers. However, you will probably get a slap on the wrist for copying.

That is why I think the industry, rather than victimising the good consumers, should compensate them by making sure that they do not need to resort to illegal activity. I really believe that if a producer values his/hers product they should stand behind it and offer a guarantee. As for keeping a copy on your PC - you cannot please everyone and still keep the product safe. It just won't work.
###This is by no means condoning or condemning piracy!!!!#####