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Modern cryptography isn't mathematically impossible to break either; you just need to put a high amount of computational resources into breaking it. And even th

Modern cryptography isn't mathematically impossible to break either; you just need to put a high amount of computational resources into breaking it. And even that is only presumably; nobody has proven yet that NP-complete problems (on whose hardness its robustness rests) cannot be solved in polynomial time. Despite all this, nobody seems to claim that cryptography is 'futile'. Sometimes mere infeasibility is enough.

amalcon 10y ago
Modern cryptography is typically in the class where, barring some mathematical breakthrough (a la the P/NP thing), it would take many times more compute resources than the Earth has for longer than the Earth will likely exist to break. Modern DRM is typically in the class where you can either spend at most a few days with a debugger and a code editor, or buy a $20 knockoff device to break it. These are not really comparable.
- j1vms 10y ago
  > (...) it would take many times more compute resources than the Earth has for longer than the Earth will likely exist to break. Claims like these are often misleading as they assume that i) malicious parties' capabilities, ii) what is and isn't possible, and iii) implementation correctness, are all static known factors. Cryptography is more akin to putting a lock on a fence - it's going to keep most people out or perhaps deter prying eyes, but it's all probabilistic in the end and depends on who's doing the prying.
tskaiser 10y ago
DRM is fundamentally broken, compared to cryptography, in that by necessity everyone has access to the keys and the content has to be decrypted to be consumed. This makes DRM a client-side security issue with some pretty bad premises. It is not a question of theory, but practice, DRM gets systematically broken all the time because of this.
legulere 10y ago
For cryptography there's a huge gap between designing and using cryptography on the one hand and breaking it on the other hand. The amount of computational resources needed for breaking it can exceed what is possible with all the energy of this universe, while encryption is still feasible with today's technology. With DRM it's usually the other way around. The attacker always has the encrypted data, the key and decryption routine. Otherwise playback wouldn't work. The only defenses are obfuscation and anti-debugging, which are basically security by obscurity. As soon as someone understands your scheme it's broken for good and you have to come up with something new. Just like with cryptography you're trying to make it as hard as possible for attackers, but with DRM it will always be around the same magnitude of difficulty as for yourself.
cryptarch 10y ago
The difference is that for DRM to be effective, it requires the DRM vendor to have full and exclusive control over some portion of your hardware. If this is not the case (and it should never be), it's breakable with resources akin to "one cracker and a Pentium IV". Crypto OTOH can be completely impractical to break. Plenty of codes around that would take even the NSA millions of years to crack, baring new mathematical or computing (e.g. quantum) breakthroughs.

amalcon 10y ago

Modern cryptography is typically in the class where, barring some mathematical breakthrough (a la the P/NP thing), it would take many times more compute resources than the Earth has for longer than the Earth will likely exist to break. Modern DRM is typically in the class where you can either spend at most a few days with a debugger and a code editor, or buy a $20 knockoff device to break it. These are not really comparable.

j1vms 10y ago
> (...) it would take many times more compute resources than the Earth has for longer than the Earth will likely exist to break. Claims like these are often misleading as they assume that i) malicious parties' capabilities, ii) what is and isn't possible, and iii) implementation correctness, are all static known factors. Cryptography is more akin to putting a lock on a fence - it's going to keep most people out or perhaps deter prying eyes, but it's all probabilistic in the end and depends on who's doing the prying.

tskaiser 10y ago

DRM is fundamentally broken, compared to cryptography, in that by necessity everyone has access to the keys and the content has to be decrypted to be consumed. This makes DRM a client-side security issue with some pretty bad premises. It is not a question of theory, but practice, DRM gets systematically broken all the time because of this.

legulere 10y ago

For cryptography there's a huge gap between designing and using cryptography on the one hand and breaking it on the other hand. The amount of computational resources needed for breaking it can exceed what is possible with all the energy of this universe, while encryption is still feasible with today's technology. With DRM it's usually the other way around. The attacker always has the encrypted data, the key and decryption routine. Otherwise playback wouldn't work. The only defenses are obfuscation and anti-debugging, which are basically security by obscurity. As soon as someone understands your scheme it's broken for good and you have to come up with something new. Just like with cryptography you're trying to make it as hard as possible for attackers, but with DRM it will always be around the same magnitude of difficulty as for yourself.

cryptarch 10y ago

The difference is that for DRM to be effective, it requires the DRM vendor to have full and exclusive control over some portion of your hardware. If this is not the case (and it should never be), it's breakable with resources akin to "one cracker and a Pentium IV". Crypto OTOH can be completely impractical to break. Plenty of codes around that would take even the NSA millions of years to crack, baring new mathematical or computing (e.g. quantum) breakthroughs.