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Analyst Says Blu-ray DRM Safe For 10 Years
Mike writes to let us know that a poster on the AVS forum says that the latest issue of HMM magazine (no link given) contains a quote from Richard Doherty, a media analyst with Envisioneering Group, extolling the strength of the DRM in Blu-ray discs, called BD+. Doherty reportedly said, "BD+, unlike AACS, which suffered a partial hack last year, won't likely be breached for 10 years." He added that if it were broken, "the damage would affect one film and one player." As one comment on AVS noted, I'll wait for the Doom9 guys to weigh in.
A link to a forum that quotes a magazine quoting a guy... something doesn't seem right here.
I give it two weeks tops. The gauntlet has been thrown down.
bash: rtfm: command not found
*queue Mortal Kombat* Test your might... MORTAL KOMBAAAAAAAT!
I won't be buying BluRay discs for at least 10+ years. I don't crybaby about DRM, I just don't buy it if it doesn't suit my needs and can't be cracked, ergo if he's right I won't buy BluRay. This is one reason I like HD-DVD, it's had the shit cracked out of it.
"With this CSS we are putting on this DVD, noone will EVER be able to copy dvds" - Some CSS guy
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A friend of my cousin's roommate said they read a comment on the wall of a bathroom at an Ohio rest stop that said you should mod the parent comment up.
There you go, fixed that for you.
* examine the host environment, to see if the player has been tampered with. Every licensed playback device manufacturer must provide the BD+ licensing authority with memory footprints that identifies their devices.
* verify that the player's keys have not been changed.
* execute native code, possibly to patch an otherwise insecure system.
* transform the audio and video output. Parts of the content will not be viewable without letting the BD+-program unscramble it. But i have to think... If it has hardware access(or can run native code) what's to say someone wont make a disk that has a BD+ program that aids in the hacking? Once you break a way around(or through) the digital signature for BD+ your whole system is compromised, how is that a good strategy?
Imagine something close to, I make a disk with a BD+ program that once I have the program loaded I can eject the disk and put in a protected one, the BD+ can help circumvent the protection, and circumvent the BD+ on that disk. Vuala! BD+ makes it easier for me to copy.
If i had one dollar for every brain you dont have, i would have $1.
What it seems like they would be talking about here would be something similar to PKE. Err, no wait that doesn't make sense, must be something like what is used in prox cards with challenge/response...hrm...not that probably isn't what it is.....OH I KNOW! every disk comes with a monkey that kicks you in the balls every time you get the disk near a computer!!
Unfortunately, this alienates most of the Chinese player manufacturing market. But it does have the bonus of coming with a free monkey.
Lets make a movie starring the DRM monkeys and then post it into the intertubes! This would send an inverse monkey (also known as a something awful member) past the event horizon, causing the entire twisted fucked up backwards universe that the movie industry lives in to collapse upon itself!!!
FREE MONKEYS FOR ALL!
NewslilySocial News. No lolcats allowed.
In case you have to eat them.
To quote Bruce Schneier, "Making bits not copyable is like trying to make water not wet." I dunno 'bout those Doom9 guys, but I know enough of Bruce Schneier's work to trust his opinion on this one. I don't know what the digital-media landscape will look like when all this settles out, but I *don't* think it'll be neatly and unbreakably wrapped in DRM containers with price tags on.
"My strength is as the strength of ten men, for I am wired to the eyeballs on espresso."
Hmm, they seem to have skipped 8. The amount of gall in this little article (which is the PDF) is amazing. AACS was "partially" cracked. BD+ is a second line of defense, four times as safe, and just like six weak locks that you don't think work, which, by the way, is magic.
What is this guy smoking?
Comment forecast: Bits of genius surrounded by a sea of mediocrity.
So far on this thread 3 dates have been suggested: 10 days, 2 weeks, and 10 weeks. This sounds like the beginning of a /. poll...
How long do you think it will take for Blu-Ray DRM to be cracked?Ben Hocking
Need a professional organizer?
the real customers, not the fringe folk who even know what DRM is.
The real customers care about what format has the most movies available.
The movie execs care about what format they feel protects and enhances their product the most.
Tada. Riddle solved. If the target audience for HD-DVD is going to be limited to "those who care about the DRM being cracked" then...HD-DVD is very, very doomed.
It wouldn't be a /. poll without missing options!
Ben Hocking
Need a professional organizer?
1) Don't even try hackers
2) Go ahead, hacker, I am taunting you.
3) Consumer, buy Blu-ray discs because your local pirate won't be stocked for years.
4) Vendor, HDDVD is hacked, go with us for more sales instead of losing untold billions in piracy.
I'm sure there is an actual reason.
God spoke to me.
Read what BD+ really is: .html
http://www.cryptography.com/technology/spdc/bluray
This means that each Blu-Ray disc has a computer program compiled to execute within a proprietary, secure VM. What this means is that each disc has a program built into it whose purpose is to boot, validate that it is running on licensed hardware, enforce security policy, and if those checks are met, extract a key from its own memory and play the content.
What does this mean for people attempting to defeat the security?
Well it means that a full crack of BD+ will require crackers to implement a virtual machine which acts in exactly the same way as the hardware VM would act. This represents a what I will casually call a "larger challenge" than defeating CSS or AACS, in which you have to decrypt a key or a list of keys. In this case, you have to come up with something which can determine the full dynamic runtime execution path of a static binary - a currently unsolved problem in Computer Science, despite numerous attempts to do such a thing by some of the world's brightest minds.
Just putting the same source code through a randomizing compiler/packer/obfuscator of the types that game companies have been working on for a while makes the challenge immensely harder. Precedent? http://spa.jssst.or.jp/summer-2005/paper/05046.pdf
There's too much to talk about.
And who's deployed this type of technology already? Who has a secure virtual machine with secure bytecode doing challenge-response to determine hardware legitimacy? People Who Care: a lot.
The other major problem is that the challenge-response authentication made by the program contained in the disc against the embedded hardware will require a "real" cert to succeed. Yes this is the TPCA/Palladium "sky is falling" scenario come to pass. Either the implementors made a cryptography implementation mistake, or someone with a scanning, tunneling electron microscope figures out how to defeat the epoxy guards and actually read the private cert material off a chip, or someone with a previously unheralded supercomputer or mathematical technique breaks the key from a known subset of challenge/response pairs... - or, it will remain unbroken. It is strong, known algorithm public key cryptography.
What's really interesting about all this is if someone DOES find a way to break BD+, there is really strong incentive for them to use it to break & release movies rather than release code which performs the break. Why? Get yourself a windows VM and download all the latest in DVD-breaking binaries: ripit4me, dvd decryptor-last, dvdshrink-last, etc. Then set windbg to be your default debugger, and start trying to break very recent DVD releases. What you'll find is that the entertainment company is employing people to literally find security holes in the input to the cracking tools - the dvd image itself, and then embed "exploits" into their dvd images. There is data on those discs that has no other purpose than to crash certain binaries. It becomes obvious once you trap execution in a debugger and know a little bit about x86 asm. Don't get me wrong, they're not executing arbitrary code, just causing a DoS - but that's only because they know they can't. Some of the conditions they've found and abused are CERTAINLY exploitable. But they also know that putting shellcode in their DVDs defeats plausible deniability, which is a hell of an asset.
Now push this knowledge forward to BD+. If someone actually manages to set up a "shim VM" that executes BD+ language and acts as a proxy between secure hardware and the bytecode, and RELEASES that VM, then we know the entertainment companies are going to enter a reverse engineering arms race. They're
PS: I love Behind the Counter.
Comment forecast: Bits of genius surrounded by a sea of mediocrity.
Do you know just how smart the guy who invented BD+ was?
Let me put it this way: have you ever heard of Plato, Aristotle, Socrates? Morons.
When they came for the communists, I said "He's next door. Take him away. Goddam commies."
how secure they make the media. Cracks will follow the path of least resistance. If every form of media moved to some form of uncrackable quantum encryption tomorrow, it wouldn't matter. Someone would crack HDCP, and the content would be available there.
If not HDCP directly, then the processor to LCD data path for some el-cheapo monitor which supports HDCP. There's always some point in the chain where protection is weak, or simply doesn't exist.
It is simply a futile endeavor as long as the consumer ultimately gets access to (i.e. can view/listen) to the content. Of course, they have no product if the consumer can't.
"National Security is the chief cause of national insecurity." - Celine's First Law
Because of Doom9's policy on links, I can't provide a direct link, but in the June news at the Doom9 website, Doom9 himself said that until the BD+ discs come out, nobody knows what will happen, but based on the spec, it is possible that it will be uncrackable. My best guess at this time is that the only way it will be cracked is if either the implementation has a gigantic hole nobody thought of (always possible) or someone gets an illegal peek at the hardware specs for the VM and is able to implement it in software. I'm not optimistic at all that BD+ will be cracked. If any of you care at all about DVD on HD formats and you want to be able to convert your future purchases in that format to other formats to watch on other devices you own such as video iPods, you better hope that BluRay fails.
So information on BD+ seems relatively hard to find. The best explanations I could find are this presentation, this pdf at dell and best of all this general discussion of SPDC.
... And I used to be rooting for Blu Ray.
The basic idea here is that BD+ allows the BluRay maker to embed virtual machine code (and apparently native code) on their disks which are then executed on the host machine. This code then somehow verifies that the host machine is uncompromised (memory footprints apparently) and then executes whatever process is necessary to decrypt the key that allows content access. Now it seems likely that there is some additional decryption process similar to AACS that decrypts the BD+ virtual code. Perhaps this decryption process is implemented better than the one in AACS but that is the only security advantage BD+ provides.
The only extra security that BD+ can offer over an AACS type system is security through obscurity. There has to be some general cryptographic process to decrypt the BD+ VM instructions. Once decrypted an attacker who is aware of the BD+ standard just needs to emulate the virtual machine and have it pretend it is a valid device to access the content. The BD+ people can talk all they want about memory footprints and tamper checks but these are just a complicated private key for the device. Separating out these functions and putting them in a VM just makes the specification of the encryption scheme more complicated (and more obscure) but doesn't fundamentally increase the security.
So why do the studies want BD+? Well maybe they've been taken in by the claims of extra security but the more plausible reason is that they want the extra control BD+ gives them over their content BD+ might not be a real impediment for the serious pirate/hacker but it does allow the movie studios to implement even more fine grained control over how you use their content. The virtual machine might be set up to prevent you from watching the movie more than once, from using a streaming feature of the device, from using it after some fixed time. Imagine, for instance, movie companies creating tiered pricing based on how many rights you want to have. Say make you pay more if you want to stream it. Disney might release their next version of Aladdin on DVD in two classes. The 'gold' class that lasts forever and the standard class that only lasts 5 years. Well you get the idea.
So no I don't buy the argument that this feature makes the system much more secure (except insofar as it might eliminate some fuckups in how the AACS system was defined) but it certainly is in the Blu Ray consortium and movie theater's interest to portray it this way. Maybe this explains the much wider adoption of Blu Ray by the theaters.
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Blu-Ray players don't contain some mystical impossible-to-duplicate VM.
It's a fucking Java VM. It's not anything bizarre. It's Java. Completely free VM implementations for Java already exist.
Oh, how do I know it's a Java VM? =) I know the people at IBM who wrote the Java VM that's used to play BD+ Blu-Ray discs on the PS3.
Since I actually do research in recursion theory (basically the mathematical study of the halting problem) let me start by saying this has ABSOLUTELY NOTHING AT ALL TO DO WITH THE HALTING PROBLEM. The halting problem, or as you stated it determine the full execution path of a static binary, is provably unsolvable because programs can take arbitrarily long before deciding to halt. Given you know a program halts (on a given input) it's trivial to determine the full execution path. Just run it and see what it does.
In this situation there is nothing at all like this going on. We know that the code on the BluRay disk produces whatever output lets you view the disk not only in finite time but after a very short time.
In fact this situation offers no additional security over a well designed public crypto system AT ALL except for obscurity. The instructions for the virtual machine are just a very complicated sort of key, one that anyone who can crack the base level encryption can view. The memory footprints and all that jazz are only fancy ways of implementing a private key.
There are damn good reasons that the people who implement public key systems and symetric ciphers don't use VM instructions as their keys. A good crypto system is built around SIMPLE and well known mathematical problems because extra complications just provide more places an attacker can find a clever short circuit that you didn't think about. The only reason to think a crypto system is secure is because you think that the attacker doesn't have any shortcuts to compute things in the other direction much faster than brute force. The more complications in your system the more places he could discover a clever trick to undermine your security.
As I argued in my other post the benefits of the BD+ VM aren't really about security but about control. It doesn't make things much harder for the hackers but it does let the content producer execute more control over when things are decrypted. The only security advantage BD+ brings is obscurity and possibly the use of a better underlying crypto system than what AACS uses (the part that decrypts the VM at the beginning).
If you liked this thought maybe you would find my blog nice too:
Trust me I'm not swimming out of my depth. I really am writing a thesis in recursion theory and I present at conferences on this stuff to the world experts in this stuff. I get paid to prove things are or are not equivalent to the halting problem.
Now it is true that for some programs determining what inputs that program halts on is an undecidable problem (consider an interpreter it executes it's input reducing this to the halting problem) Hence the reason I was quite careful to specify that I was talking about a program known to halt '(on a given input)'. In case that wasn't clear let me spell out the theorem more precisely: there is a program S(i,x) so that if the i-th Turing machine halts on input x S(i,x) outputs the states (tuples of tape, head etc..) that Turing machine enters while executing on that input. I mean fuck if we really want to get stupid about this there are only a finite number of programs/input pairs that could be encoded in all the molecules used by the Blu Ray disk/player so there is some program (a giant case statement) that tells you how each one of them behaves.
Of course such a program is totally useless and irrelevant to the question of cryptography. Thus the reason I pointed out that the halting problem simply doesn't apply here. The question in cryptography is not whether something can be computed but whether it can be done so efficiently.
--
Now I won't claim to be an expert in cryptography the same way I am in recursion theory aka computability theory but I do know a fair bit about it (being a mathematician some stuff leaks out) and you are pretty confused.
Just consider the S-box in a normal symmetric cipher (like DES). This tells you how to modify some of the bits of your input based on the value of other bits, i.e., the value of some bits of the content you are decrypting tells you how to change the value of other bits. If you wanted to you could describe this just the same way you did the BD+ VM system. Each encrypted piece of content comes along with instructions that execute on the S-box VM (and lots of other components) that tell you how to modify other bits of the input.
Any block cipher works by letting some bits read from the input affect how you decrypt other bits. The only question is how you do it. If you could make your cryptographic algorithm more secure by exchanging nice simple things like S-boxes for complex computer like VMs they would be doing it.
So what about your claim that BD+ lets them modify the cryptography after a break making it more secure? Well like AACS does, they can revoke the keys of compromised devices but the VM plays no role here. BD+ can't do more than this as Blu Ray players bought next year need to be able to play Blu Ray disks in 3 years which means there must be some pre-established algorithm that lets the current players decode the future disks. That algorithm IS the cryptosystem, calling it a VM doesn't change anything.
At the highest level of abstraction things ALWAYS look like this. Player has some secret information. The information on the disk is somehow encrypted so that it is (supposed to be) hard to compute the content stream without the secret info. The player applies some algorithm (in this case runs the virtual code in a VM after doing some other cryptographic verification) that then produces the content stream as a function of the player secret and the data on the disk. Making this function more complex by sticking a VM inside it only makes the decryption algorithm more obscure. Once you've figured out the algorithm in the BD+ docs, i.e., the non-secret part all the manufacturers get, it's just another cryptosystem.
The reason the Palladium/TPM people use VMs and the like isn't because they make things more secure. If all you wanted to do was prevent unauthorized people from reading your HD you would just encrypt it with a nice symmetric cipher and be done. They implement a VM because it gives them more control. So long as the system'
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