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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

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 breaking Blu-Ray one person has to rip it to 1080p video and the rest can download it...

tptacek 15y ago
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.
- X-Istence 15y ago
  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.
  - tptacek 15y ago
    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.
    - mikeash 15y ago
      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.
      - tptacek 15y ago
        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).

tptacek 15y ago

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.

X-Istence 15y ago
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.
- tptacek 15y ago
  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.
  - mikeash 15y ago
    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.
    - tptacek 15y ago
      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).