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> By the way: If the FBI is so successful using traditional police tactics to infiltrate "cybercrime syndicates," why do they need a "front door" to our devices

by mpyne 12y ago

> By the way: If the FBI is so successful using traditional police tactics to infiltrate "cybercrime syndicates," why do they need a "front door" to our devices? Just like the old-fashioned police work they did here which you mentioned, the FBI in the past has been able to use warrants to obtain unilateral access to safe deposit boxes, drill open personal safes stored at home, search through a person's desks, closets, bedrooms, etc. for particular items, and more. That is the level of access FBI Director Comey is saying that they need (the ability to enforce warrants for the same types of searches required for "papers and effects") for the same reasons that the FBI has needed such access for investigations in the past. He isn't asking for the ability to conduct passive or mass surveillance, or even the ability for FBI to unilaterally enforce a warrant. He's asking for the ability of the device manufacturer themselves to be able to comply with a warrant if one is offered up. The cryptographic technology necessary to do so already exists, in a way that would limit access to the manufacturer, so that's not the issue.

girvo 12y ago
> The cryptographic technology necessary to do so already exists, in a way that would limit access to the manufacturer, so that's not the issue. This is a genuine question: Does it really? Everything I've read on the topic has shown that that's not really the case, at least not without implementing it in such a way that it has some rather serious human weaknesses anyway. However, I'm rather ignorant on the topic, so I'm genuinely curious.
- mpyne 12y ago
  Easy mode is to encrypt the device key for each individual device, store it only with the manufacturer. Make it more difficult by requiring m-of-n agreement (probably via a parity block scheme) between HSMs to derive the key if you wish (with the key material being guarded on separate stores so that an insider can't simply hack into access), but that's not that difficult in comparison to what we're talking about. Even easier might be to have the device itself store an encrypted version of the data storage key, encrypted to a PKI private key that only the manufacturer controls (i.e. leave a GPG-encrypted file accessible in an unencrypted partition that unlocks the rest of the storage). Since we're assuming that skilled hackers will forcibly encrypt sensitive data anyways by jailbreaking if needed, it's not that much of an additional stretch to leave the key on the device itself, and FBI can still get warrants served on the 99.9% of accused criminals who can't be arsed to figure out that their iPhone can be unlocked. I'm not even close to a crypto expert either, someone with deep insight into the crypto literature (I hear NSA has a few of those...) could undoubtedly point to more applicable research that would be useful here.

by mpyne 12y ago

girvo 12y ago

> The cryptographic technology necessary to do so already exists, in a way that would limit access to the manufacturer, so that's not the issue. This is a genuine question: Does it really? Everything I've read on the topic has shown that that's not really the case, at least not without implementing it in such a way that it has some rather serious human weaknesses anyway. However, I'm rather ignorant on the topic, so I'm genuinely curious.

mpyne 12y ago
Easy mode is to encrypt the device key for each individual device, store it only with the manufacturer. Make it more difficult by requiring m-of-n agreement (probably via a parity block scheme) between HSMs to derive the key if you wish (with the key material being guarded on separate stores so that an insider can't simply hack into access), but that's not that difficult in comparison to what we're talking about. Even easier might be to have the device itself store an encrypted version of the data storage key, encrypted to a PKI private key that only the manufacturer controls (i.e. leave a GPG-encrypted file accessible in an unencrypted partition that unlocks the rest of the storage). Since we're assuming that skilled hackers will forcibly encrypt sensitive data anyways by jailbreaking if needed, it's not that much of an additional stretch to leave the key on the device itself, and FBI can still get warrants served on the 99.9% of accused criminals who can't be arsed to figure out that their iPhone can be unlocked. I'm not even close to a crypto expert either, someone with deep insight into the crypto literature (I hear NSA has a few of those...) could undoubtedly point to more applicable research that would be useful here.