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It's ironic: In many ways, the simplest problems are the hardest for hackers to solve. We naturally understand programs and protocols that flummox average users

It's ironic: In many ways, the simplest problems are the hardest for hackers to solve. We naturally understand programs and protocols that flummox average users, including PGP and Bitcoin. Donning the veil of techno-ignorance is an elusive skill, so it can take a long time to figure out how something valuable can be reduced to a truly idiot-proof format. Lots of different approaches to encryption have pitched themselves as the easy-to-use replacement for PGP. Alas, so far, none of them have taken the world by storm.

sillysaurus3 11y ago
Lots of different approaches to encryption have pitched themselves as the easy-to-use replacement for PGP. Alas, so far, none of them have taken the world by storm. That's good, though. PGP is the only one that's given true safety. Everything else has broken, either in theory or (mostly) in implementation. The problem is a social one, and it doesn't need to be solved quickly. It's fine if it takes several more decades before we find the right model. Those that want to protect themselves can do so. Those that don't, don't. Not such a bad outcome, all things considered. It seems like PGP's web of trust model was the mistake, anyway. There's not much wrong with the model of "here's my pubkey, and now you can send me data securely." The key can be intercepted or subverted, but what changed since the 80's was the rise of instant messaging. In 2015, you're often talking to people in realtime, and you want to talk and send data to them securely. To do that, you're exchanging keys in realtime, over some kind of chat program. (Even emailing someone a pubkey counts as a form of chat.) In that context, the web of trust is unnecessary.
- toothbrush 11y ago
  Emailing somebody your public key sounds like a really bad idea. What about your friend's evil sysadmin who replaces the public key that you sent with another one, thereby enabling MITM? You might as well not use PGP in that case. Of course, once your friend has established that it was indeed your public key, it's all fine, but doing initial key exchange over unauthenticated channels sounds like a recipe for disaster.
  - ClintEhrlich 11y ago
    I haven't fully figured out the solution (if I had, I'd be writing it), but I suspect it will ultimately involve the widespread availability of smartphones and laptops with the capacity to record and transmit video. For the time being, the human face and voice are a fairly robust medium for embedding data in a way that is resistant to MITM.
  - mitchtbaum 11y ago
    > What about your friend's evil sysadmin who replaces the public key that you sent with another one, thereby enabling MITM? You could also send with it detached key signatures from mutually trusted friends. This would add weight to your claim that this key belongs to you. Then, your recipient can check that your message's contents (including your pubkey) are signed by a key that your receiver can adequately measure authenticity. Does that seem right? If a hostile MITM modifies your message and/or your key and signature, then these friend's signatures won't match. If they change these signatures as well, then those won't match the receiver's already trusted keys. [Aside: One other way I have played with was to rate another signed message by a friend (who sent me his pubkey as an email attachment) with a likelihood that he wrote it, and then I checked if that message's signature matched. As a qualitative heuristic test, it did increase my confidence in that key significantly, though I would have liked to have some trusted 3rd parties witness his possession of it.]
mitchtbaum 11y ago
> Donning the veil of techno-ignorance is an elusive skill How can someone gain this skill?
- hollerith 11y ago
  At Palo Alto Research Center in the 1970s, they brought children into their lab and watched as they used or played with the then-new graphical user interfaces.

sillysaurus3 11y ago

Lots of different approaches to encryption have pitched themselves as the easy-to-use replacement for PGP. Alas, so far, none of them have taken the world by storm. That's good, though. PGP is the only one that's given true safety. Everything else has broken, either in theory or (mostly) in implementation. The problem is a social one, and it doesn't need to be solved quickly. It's fine if it takes several more decades before we find the right model. Those that want to protect themselves can do so. Those that don't, don't. Not such a bad outcome, all things considered. It seems like PGP's web of trust model was the mistake, anyway. There's not much wrong with the model of "here's my pubkey, and now you can send me data securely." The key can be intercepted or subverted, but what changed since the 80's was the rise of instant messaging. In 2015, you're often talking to people in realtime, and you want to talk and send data to them securely. To do that, you're exchanging keys in realtime, over some kind of chat program. (Even emailing someone a pubkey counts as a form of chat.) In that context, the web of trust is unnecessary.

toothbrush 11y ago
Emailing somebody your public key sounds like a really bad idea. What about your friend's evil sysadmin who replaces the public key that you sent with another one, thereby enabling MITM? You might as well not use PGP in that case. Of course, once your friend has established that it was indeed your public key, it's all fine, but doing initial key exchange over unauthenticated channels sounds like a recipe for disaster.
- ClintEhrlich 11y ago
  I haven't fully figured out the solution (if I had, I'd be writing it), but I suspect it will ultimately involve the widespread availability of smartphones and laptops with the capacity to record and transmit video. For the time being, the human face and voice are a fairly robust medium for embedding data in a way that is resistant to MITM.
- mitchtbaum 11y ago
  > What about your friend's evil sysadmin who replaces the public key that you sent with another one, thereby enabling MITM? You could also send with it detached key signatures from mutually trusted friends. This would add weight to your claim that this key belongs to you. Then, your recipient can check that your message's contents (including your pubkey) are signed by a key that your receiver can adequately measure authenticity. Does that seem right? If a hostile MITM modifies your message and/or your key and signature, then these friend's signatures won't match. If they change these signatures as well, then those won't match the receiver's already trusted keys. [Aside: One other way I have played with was to rate another signed message by a friend (who sent me his pubkey as an email attachment) with a likelihood that he wrote it, and then I checked if that message's signature matched. As a qualitative heuristic test, it did increase my confidence in that key significantly, though I would have liked to have some trusted 3rd parties witness his possession of it.]

mitchtbaum 11y ago

> Donning the veil of techno-ignorance is an elusive skill How can someone gain this skill?

hollerith 11y ago
At Palo Alto Research Center in the 1970s, they brought children into their lab and watched as they used or played with the then-new graphical user interfaces.