5 ms·

The hardest problem, IMHO, has been key management. How do you get+trust the other's key? I think a combination of keybase + a useful client can help, but the

The hardest problem, IMHO, has been key management. How do you get+trust the other's key? I think a combination of keybase + a useful client can help, but the reasons listed in parent are pretty convincing.

Sunset 10y ago
>How do you get+trust the other's key? Snail mail + several other out of band methods. Or you can exchange a one time pad, physically.
- cvwright 10y ago
  This also raises the question: With a walled garden like Signal/Wire/etc, how do you get+trust the other's key? Their convenience comes at a cost.
  - maxerickson 10y ago
    There are mechanisms to use out of band communication to verify a key: https://github.com/WhisperSystems/Signal-iOS/wiki/FAQ#can-i-verify-the-safety-number https://github.com/WhisperSystems/Signal-iOS/wiki/FAQ#can-i-... https://support.wire.com/hc/en-us/articles/207692235-How-can-I-compare-key-fingerprints- https://support.wire.com/hc/en-us/articles/207692235-How-can...
    - cvwright 10y ago
      Yup, and I've done these. But you can do similar things with PGP public keys, too.
      - maxerickson 10y ago
        I don't understand. You've verified a Signal key but still felt the need to ask the question With a walled garden like Signal/Wire/etc, how do you get+trust the other's key? What cost were you talking about then?
        cvwright 10y ago
        Sorry if my earlier comment came off as rude. I was just trying to say that the walled gardens aren't really that much better than plain old PGP, and in practice they tend to lull people into a false sense of security. I think too many people are way too trusting of shiny new apps with a pretty UI. If you don't do the extra work of verifying the key, you're effectively letting the service provider act as your one and only CA. If you can verify a Signal key fingerprint, you can verify a PGP public key fingerprint.
        maxerickson 10y ago
        I didn't think it was rude, it just contradicted your other comment. I still don't see what cost you were speaking about. Mistakes with PGP are at least as likely as mistakes with the shiny easy to use GUI.
  - x0x0 10y ago
    One idea: send them a signal (hi, this you?) then immediately dial their number and confirm.
    - skierscott 10y ago
      Ideally dual channel. Send them a message on their mobile phone, call on the home phone (if they have one).
mikegerwitz 10y ago
If you care about the physical identity of someone: web of trust. At some point, you'll have to ideally meet at least one person in the flesh to exchange keys and verify their identity. After that point, it's possible that others you are trying to communicate with might be within your web of trust. If not, you'll have to go through your keysigning procedure again. https://www.gnupg.org/gph/en/manual/x334.html Some organizations facilitate keysigning: https://wiki.debian.org/Keysigning/Coordination But that might not be necessary for you. For example, I don't necessarily care about the physical identity for some of the people I communicate with online. If I see in e-mail archives that person is using the same key to sign their mail for the past N years, I'll use that key to encrypt to them. Similarly with commit signing and such. In that case, I just care that my message is reaching the intended recipient. I communicate with a number of GNU hackers. Package maintainers upload their signing keys to Savannah, and sign each of their releases with that key. If I simply want to know that my message is reaching that maintainer, I can get the key that way. But if I want to know that I'm actually speaking to the person that the maintainer _claims_ to be, I'd want to use the web of trust. They could very well be an imposter!
- zeveb 10y ago
  > After that point, it's possible that others you are trying to communicate with might be within your web of trust. The problem with the web of trust is that it simply doesn't work: the fact that I know you means nothing about whether I trust you to vouch for others. The fact that I trust you to vouch for employees of Acme Widgets means nothing about whether I trust you to vouch for members of the a political party. PGP's usable despite the fact that the Web of Trust is kinda a misfeature.
  - coldtea 10y ago
    >The problem with the web of trust is that it simply doesn't work: the fact that I know you means nothing about whether I trust you to vouch for others. Actually it means a lot. That's how trust works in the real world as well.
    - 10y ago
dredmorbius 10y ago
TOFU works within a number of contexts. Though not all. Generally, out-of-band or reference-based (e.g., third-party vouching) of identity. Web-of-trust is useful but IMO ultimately a tool of limited use, and presents numerous issues with data disclosure, as it is an independent and public validation of social networks. Often who knows who is more critical than who says what to whom. PGP-over-email unfortunately leaks massive amounts of metadata.

Sunset 10y ago

>How do you get+trust the other's key? Snail mail + several other out of band methods. Or you can exchange a one time pad, physically.

cvwright 10y ago
This also raises the question: With a walled garden like Signal/Wire/etc, how do you get+trust the other's key? Their convenience comes at a cost.
- maxerickson 10y ago
  There are mechanisms to use out of band communication to verify a key: https://github.com/WhisperSystems/Signal-iOS/wiki/FAQ#can-i-verify-the-safety-number https://github.com/WhisperSystems/Signal-iOS/wiki/FAQ#can-i-... https://support.wire.com/hc/en-us/articles/207692235-How-can-I-compare-key-fingerprints- https://support.wire.com/hc/en-us/articles/207692235-How-can...
  - cvwright 10y ago
    Yup, and I've done these. But you can do similar things with PGP public keys, too.
    - maxerickson 10y ago
      I don't understand. You've verified a Signal key but still felt the need to ask the question With a walled garden like Signal/Wire/etc, how do you get+trust the other's key? What cost were you talking about then?
      - cvwright 10y ago
        Sorry if my earlier comment came off as rude. I was just trying to say that the walled gardens aren't really that much better than plain old PGP, and in practice they tend to lull people into a false sense of security. I think too many people are way too trusting of shiny new apps with a pretty UI. If you don't do the extra work of verifying the key, you're effectively letting the service provider act as your one and only CA. If you can verify a Signal key fingerprint, you can verify a PGP public key fingerprint.
        maxerickson 10y ago
        I didn't think it was rude, it just contradicted your other comment. I still don't see what cost you were speaking about. Mistakes with PGP are at least as likely as mistakes with the shiny easy to use GUI.
- x0x0 10y ago
  One idea: send them a signal (hi, this you?) then immediately dial their number and confirm.
  - skierscott 10y ago
    Ideally dual channel. Send them a message on their mobile phone, call on the home phone (if they have one).

mikegerwitz 10y ago

If you care about the physical identity of someone: web of trust. At some point, you'll have to ideally meet at least one person in the flesh to exchange keys and verify their identity. After that point, it's possible that others you are trying to communicate with might be within your web of trust. If not, you'll have to go through your keysigning procedure again. https://www.gnupg.org/gph/en/manual/x334.html Some organizations facilitate keysigning: https://wiki.debian.org/Keysigning/Coordination But that might not be necessary for you. For example, I don't necessarily care about the physical identity for some of the people I communicate with online. If I see in e-mail archives that person is using the same key to sign their mail for the past N years, I'll use that key to encrypt to them. Similarly with commit signing and such. In that case, I just care that my message is reaching the intended recipient. I communicate with a number of GNU hackers. Package maintainers upload their signing keys to Savannah, and sign each of their releases with that key. If I simply want to know that my message is reaching that maintainer, I can get the key that way. But if I want to know that I'm actually speaking to the person that the maintainer _claims_ to be, I'd want to use the web of trust. They could very well be an imposter!

zeveb 10y ago
> After that point, it's possible that others you are trying to communicate with might be within your web of trust. The problem with the web of trust is that it simply doesn't work: the fact that I know you means nothing about whether I trust you to vouch for others. The fact that I trust you to vouch for employees of Acme Widgets means nothing about whether I trust you to vouch for members of the a political party. PGP's usable despite the fact that the Web of Trust is kinda a misfeature.
- coldtea 10y ago
  >The problem with the web of trust is that it simply doesn't work: the fact that I know you means nothing about whether I trust you to vouch for others. Actually it means a lot. That's how trust works in the real world as well.
  - 10y ago

dredmorbius 10y ago

TOFU works within a number of contexts. Though not all. Generally, out-of-band or reference-based (e.g., third-party vouching) of identity. Web-of-trust is useful but IMO ultimately a tool of limited use, and presents numerous issues with data disclosure, as it is an independent and public validation of social networks. Often who knows who is more critical than who says what to whom. PGP-over-email unfortunately leaks massive amounts of metadata.