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iBooks DRM has been cracked.

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Re: iBooks DRM has been cracked.

#51

Post by X-Istence »

tptacek wrote: post #47
X-Istence wrote: post #45

Earlier quoted context omitted.

The crypto cards in modern satellite TV systems haven't remained unbroken. I know of several people personally that are pirating satellite TV right now. It just required a lot more work and physical access to hardware and not just a simple software hack. The other thing about satellite TV is that once broken for one person the knowledge has to be given to many other people for them to gain anything from it. With brea…

This isn't so much a refutation of my comment as it is a quibble about what it means to be "broken". A little over a decade ago, any moron could visit one of several web sites, pay around $100, and have shipped to them everything they needed to watch DirecTV for free. Today, you apocryphally know of several people who are pirating satellite TV. I'm going to go ahead and call this one for DirecTV.

Sure, it is a lot more limited to just certain people (mostly hardware hackers) but that doesn't mean it isn't broken.

Sure, call it for DirectTV/Dish, I would definitely agree that they have raised the bar significantly. I know several of the people working at Dish that are working to make it even harder (and they do toy with the hackers :P).

We still consider md5 broken, even-though finding collisions that make a real world difference is still considered difficult and isn't done by the layman.

Re: iBooks DRM has been cracked.

#52

Post by ars »

tzs wrote: post #31

There's one thing about cracking DRM that has me puzzled. Consider DRM on music, for instance. Suppose we have a 4 minute song, stored as an MP3 with DRM. The ideal crack results in a 4 minute audio file, without DRM, that is the same audio quality as the input MP3, and is about the same size. If we didn't care about size, there would be an easy way to crack the DRM. Just play back to music and capture the digital au…

Actually, MP3 should in fact do that. Assuming you added no noise, reencoding an MP3 should give you the identical stream.

Of course should doesn't equal does, but I believe that MP3's do reencode pretty well.

Re: iBooks DRM has been cracked.

#53

Post by tptacek »

X-Istence wrote: post #51
tptacek wrote: post #47

Earlier quoted context omitted.

This isn't so much a refutation of my comment as it is a quibble about what it means to be "broken". A little over a decade ago, any moron could visit one of several web sites, pay around $100, and have shipped to them everything they needed to watch DirecTV for free. Today, you apocryphally know of several people who are pirating satellite TV. I'm going to go ahead and call this one for DirecTV.

Sure, it is a lot more limited to just certain people (mostly hardware hackers) but that doesn't mean it isn't broken. Sure, call it for DirectTV/Dish, I would definitely agree that they have raised the bar significantly. I know several of the people working at Dish that are working to make it even harder (and they do toy with the hackers :P). We still consider md5 broken, even-though finding collisions that make a r…

This attitude is one reason nerds have such a hard time reasoning about software protection.

The fact is, DRM isn't an academic exercise. It's software written in order to make content producers money by (for the most part) protecting the new-release window of new titles (or, in DTV's case, by making it riotously expensive to pirate satellite TV).

Nerds look at the graph of facts around any given DRM scheme, create the all-pairs shortest path of conclusions in their head, discover one or more cases in which the DRM scheme isn't perfect, and declare it "broken". But business owners could care less: as long as the title is making more money, DRM was a win for them.

Somewhat tangentially: MD5 is still unbroken in some constructions.

Re: iBooks DRM has been cracked.

#54

Post by tptacek »

shalmanese wrote: post #49
DarkShikari wrote: post #5

I’ve always thought that DRM only remained unbroken so long as no hacker was interested in breaking it This has always been true; why break the weak DRM on a low-quality 'Netflix' stream when you can do an HDTV rip or even a Blu-ray rip? But the instant you create exclusive content that everyone wants on such a service, the DRM will be broken faster than you can say "DMCA". The downside of this is it lets companies d…

"When StarForce 3.0 was released, it initially provided extremely strong protection - the StarForce 3.0-protected game Splinter Cell: Chaos Theory was uncracked for 424 days.[11][12] It also marked a significant step up in the effort required to reverse engineer it.[13]" http://en.wikipedia.org/wiki/StarForce

Starforce, for those here not familiar with it, is essentially a very competently designed kernel rootkit: it installs a VM in kernel mode triggered by interrupt handlers, hooks nt!SwapContext to track every execution context on the system, and basically runs as a resident service to decrypt functions in game titles on demand.

Re: iBooks DRM has been cracked.

#55

Post by mikeash »

tptacek wrote: post #53
X-Istence wrote: post #51

Earlier quoted context omitted.

Sure, it is a lot more limited to just certain people (mostly hardware hackers) but that doesn't mean it isn't broken. Sure, call it for DirectTV/Dish, I would definitely agree that they have raised the bar significantly. I know several of the people working at Dish that are working to make it even harder (and they do toy with the hackers :P). We still consider md5 broken, even-though finding collisions that make a r…

This attitude is one reason nerds have such a hard time reasoning about software protection. The fact is, DRM isn't an academic exercise. It's software written in order to make content producers money by (for the most part) protecting the new-release window of new titles (or, in DTV's case, by making it riotously expensive to pirate satellite TV). Nerds look at the graph of facts around any given DRM scheme, create t…

DRM is broken as a theoretical construct.

MD5 is broken, but the concept of cryptographic hashes is solid. There's no theoretical problem with the idea of a function where f(a) != f(b) implies a != b to an extremely high probability. The only trick is coming up with real-world systems which approach the theoretical ideal.

DRM, on the other hand, is a theoretical impossibility. It aims to show content without allowing it to be copied, which is a concept that makes no sense. In practice it can work to an extent, but this is only done by coming up with real-world systems which run in the opposite direction from the theoretical ideal.

I'm not at all convinced that business owners couldn't care less. They keep raising the bar, both technologically and legally. Breaking DRM, even for purposes that would otherwise be legitimate, has been illegal in the US for over a decade now. And this is ultimately the crux of the problem, and what causes people to frustratedly declare that DRM is a broken concept. It is a crime to express certain mathematical concepts, and the only reason that's the case is because businesses make up for the lack of theoretical rigor in DRM by bringing in the power of the law.

Imagine if the cryptographic community's response to the break of MD5 was to lobby for a law that made it illegal to generate hash collisions or create or distribute code that could do that, because theory prohibited anything substantially better than MD5 from being produced. MD5 is still a useful hash through the present day and well into the future, but in that hypothetical and counter-factual situation, I think it would be reasonable to call the concept of cryptographic hashing broken.

Re: iBooks DRM has been cracked.

#56

Post by tptacek »

mikeash wrote: post #55
tptacek wrote: post #53

Earlier quoted context omitted.

This attitude is one reason nerds have such a hard time reasoning about software protection. The fact is, DRM isn't an academic exercise. It's software written in order to make content producers money by (for the most part) protecting the new-release window of new titles (or, in DTV's case, by making it riotously expensive to pirate satellite TV). Nerds look at the graph of facts around any given DRM scheme, create t…

DRM is broken as a theoretical construct. MD5 is broken, but the concept of cryptographic hashes is solid. There's no theoretical problem with the idea of a function where f(a) != f(b) implies a != b to an extremely high probability. The only trick is coming up with real-world systems which approach the theoretical ideal. DRM, on the other hand, is a theoretical impossibility. It aims to show content without allowing…

We're talking past each other. I'm stipulating that DRM is "broken theoretically" and arguing that it doesn't matter.

I'm also pointing out that MD5, though "broken" is actually cryptographically viable in some constructions --- in other words, there are cryptographic applications of MD5 that have no known viable attacks, even though MD5 is itself a weak hash. It's a tangent, but I thought a telling one: even though the nerdy vantage point is "MD5 is broken, avoid at all costs!", the reality is that it still works in some settings. Just like DRM.

Finally, if you want to reason through the legalities of DRM laws, start thinking in terms of contract law instead of technology. The reason content owners would like it to be unlawful to break DRM is that they shouldn't need to incur an arms race merely to enforce otherwise binding contracts. The fact is that it is entirely lawful to make access to an entertainment title conditioned on acceptance of a contract not to distribute the title. Violating that contract is unlawful. DRM exists in order to make it harder to violate binding contracts. In fact, the laws regarding DRM even anticipate the hardships DRM creates for normal users, and creates exceptions for breaking DRM in cases of interoperability and security research.

It is no case a "crime" to express mathematical concepts, except under exceedingly silly definitions of the term "mathematical concept" (any piece of content can of course be described mathematically; that doesn't make it lawful for me to steal and publish your credit card number).

Re: iBooks DRM has been cracked.

#57

Post by [deleted] »

teamonkey wrote: post #27
Retric wrote: post #21

Earlier quoted context omitted.

Considering it rarely takes a week for a popular games DRM to be broken the window between copy protection and the lack there of does not necessarily mean much. What many people forget is there will always be leechers out there but there are also people who will make the moral choice and buy the content. PS: I will torrent a show I my DVR fills up or something. But, I don't cancel cable and download everything and I…

> Considering it rarely takes a week for a popular games DRM to be broken the window between copy protection and the lack there of does not necessarily mean much. It means a lot because the majority of a game's total sales will be in the first 3 weeks. After one month, you're more or less done. Very few games have any sort of tail, let alone a long one. [EDIT: I'm speaking in general for high-profile retail games] As…

[deleted]

Re: iBooks DRM has been cracked.

#58

Post by Retric »

tptacek wrote: post #29
teamonkey wrote: post #27

Earlier quoted context omitted.

> Considering it rarely takes a week for a popular games DRM to be broken the window between copy protection and the lack there of does not necessarily mean much. It means a lot because the majority of a game's total sales will be in the first 3 weeks. After one month, you're more or less done. Very few games have any sort of tail, let alone a long one. [EDIT: I'm speaking in general for high-profile retail games] As…

Based on my understanding of the market from friends who work in this space, this is exactly correct.

I can point to games that I did not buy specifically because they had horrible DRM. Most notably Crisis 2 and Spore which I had reordered and then canceled after I read how bad the DRM was. Granted the fact they both got many poor reviews also helped that decision. But, DRM costs company's significant amounts of money to deploy and also costs them sales.

Now done well or even just unobtrusively DRM clearly can work, most notably with consoles, phones, and Steam. My point is simply buying 48, hours which is considered a success in many DRM circles, does not mean you actually benefit monetarily you need to look beyond time to crack in expectations that it will be cracked and how enticing you can make the guided cage. It's possible to make always on DRM orders of magnitude harder to crack but doing so will cost you many upfront sales some of whom will wait for that first crack unless being online is already inherent to game play.

Re: iBooks DRM has been cracked.

#59

Post by teamonkey »

Retric wrote: post #58
tptacek wrote: post #29

Earlier quoted context omitted.

Based on my understanding of the market from friends who work in this space, this is exactly correct.

I can point to games that I did not buy specifically because they had horrible DRM. Most notably Crisis 2 and Spore which I had reordered and then canceled after I read how bad the DRM was. Granted the fact they both got many poor reviews also helped that decision. But, DRM costs company's significant amounts of money to deploy and also costs them sales. Now done well or even just unobtrusively DRM clearly can work,…

> But, DRM costs company's significant amounts of money to deploy and also costs them sales.

Not necessarily true on either count.

Re: iBooks DRM has been cracked.

#60

Post by mikeash »

tptacek wrote: post #56
mikeash wrote: post #55

Earlier quoted context omitted.

DRM is broken as a theoretical construct. MD5 is broken, but the concept of cryptographic hashes is solid. There's no theoretical problem with the idea of a function where f(a) != f(b) implies a != b to an extremely high probability. The only trick is coming up with real-world systems which approach the theoretical ideal. DRM, on the other hand, is a theoretical impossibility. It aims to show content without allowing…

We're talking past each other. I'm stipulating that DRM is "broken theoretically" and arguing that it doesn't matter. I'm also pointing out that MD5, though "broken" is actually cryptographically viable in some constructions --- in other words, there are cryptographic applications of MD5 that have no known viable attacks, even though MD5 is itself a weak hash. It's a tangent, but I thought a telling one: even though…

The illegality of distributing a title without permission has nothing to do with contract law. It's a basic principle of copyright. No contract needs to be in place, explicit or implicit, to prevent that.

DRM does not solely exist to make it harder to violate that law. DRM also exists to prevent use of the buyer's own rights. DRM prevents fair use as well as infringement, and I'm pretty sure the media companies consider this to be a feature, not a bug.

When I say "mathematical concepts", I'm talking about algorithms, not content. I think that e.g. the core of DeCSS qualifies as a mathematical concept, and it's illegal to express it under current US law, although that law is widely ignored.

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