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As internet users we are provided with a folder or a file full of "certificates" by some item of software, e.g., an operating system, a web browser, etc. In so

As internet users we are provided with a folder or a file full of "certificates" by some item of software, e.g., an operating system, a web browser, etc. In some cases, we have the choice of removing certain certificates if we do not trust them or adding certificates that we choose to trust. People online like to make assertions and argue about a so-called "chain of trust". What if that "chain of trust" began with the user, not a third party? In other words, the user created her own certificate (the root), then selected and signed the "trusted" ones provided to her that she deemed trustworthy? The software would not be able to bypass the user's trust. Just because an "approved" third party signed a certificate does not in and of itself consitute trustworthiness by the user.

Nursie 6y ago
I wish you luck explaining this to the average user.
vbezhenar 6y ago
Basically that's called web of trust and was implemented by GPG for decades. It seems that even geeks don't really use that.
- tialaramex 6y ago
  The Web of Trust approach can only scale by treating Trust as Transitive. If your trust is confined to a few dozen co-conspirators it all works fine. But when you try scale up it breaks badly because human trust is not actually transitive. PGP tries to fix that by asking you about two things, in the process further worsening the UX. PGP asks Alice if she believes this key is Bob, and then also if she trusts Bob to decide who other people are for her. Very quickly Alice will discover that unless she agrees to allow multiple such transitive trust steps the "Web of trust" doesn't do much for her. Hopefully she gives up at this point. But if she keeps using it, then eventually the other shoe drops. Alice sends a message to "Frank" which she intends to keep secret. But unfortunately it doesn't actually go to Frank, the "Frank" identity was vouched for by Edgar. Alice trusted Bob, who trusted Carol, and Carol trusted Dana, and unfortunately Dana is a poor judge of character and trusted Edgar who isn't very reliable.
  - pwdisswordfish2 6y ago
    Human trust is not actually transitive. Is this like saying human trust cannot be 100% delegated? If so, that seems to be the model of the third party CA system. As a user I really have little say in "who", e.g., the web browser, should trust. I have (unintentionally) delegated trust to third parties. They decide who I should trust. As a user, I am not supposed to care about or understand this process. This really does not sound like "authentication" to me because I have not authenticated anything. Everything is being handled by third parties.
    - tialaramex 6y ago
      A conventional PKI ("the third party CA system") separates out this authority. You trust Trent to discern who Bob, Carol, Dana, Edgar and Frank are. In choosing to engage in conversation with Dana, or even Edgar, you are not obliged to accept their word as to the identity of Frank, that's always Trent's job. And so Edgar's unreliability and Dana's poor character judgement aren't a problem.
      - pwdisswordfish2 6y ago
        What if I already know "Carol"? Should a web browser block me from "conversing with Carol" because I did not get "Trent's" approval first? Seems like I should be the one who decides whether I approve of Carol or not. I am the one taking the risk of "having the conversation".

Nursie 6y ago

I wish you luck explaining this to the average user.

vbezhenar 6y ago

Basically that's called web of trust and was implemented by GPG for decades. It seems that even geeks don't really use that.

tialaramex 6y ago
The Web of Trust approach can only scale by treating Trust as Transitive. If your trust is confined to a few dozen co-conspirators it all works fine. But when you try scale up it breaks badly because human trust is not actually transitive. PGP tries to fix that by asking you about two things, in the process further worsening the UX. PGP asks Alice if she believes this key is Bob, and then also if she trusts Bob to decide who other people are for her. Very quickly Alice will discover that unless she agrees to allow multiple such transitive trust steps the "Web of trust" doesn't do much for her. Hopefully she gives up at this point. But if she keeps using it, then eventually the other shoe drops. Alice sends a message to "Frank" which she intends to keep secret. But unfortunately it doesn't actually go to Frank, the "Frank" identity was vouched for by Edgar. Alice trusted Bob, who trusted Carol, and Carol trusted Dana, and unfortunately Dana is a poor judge of character and trusted Edgar who isn't very reliable.
- pwdisswordfish2 6y ago
  Human trust is not actually transitive. Is this like saying human trust cannot be 100% delegated? If so, that seems to be the model of the third party CA system. As a user I really have little say in "who", e.g., the web browser, should trust. I have (unintentionally) delegated trust to third parties. They decide who I should trust. As a user, I am not supposed to care about or understand this process. This really does not sound like "authentication" to me because I have not authenticated anything. Everything is being handled by third parties.
  - tialaramex 6y ago
    A conventional PKI ("the third party CA system") separates out this authority. You trust Trent to discern who Bob, Carol, Dana, Edgar and Frank are. In choosing to engage in conversation with Dana, or even Edgar, you are not obliged to accept their word as to the identity of Frank, that's always Trent's job. And so Edgar's unreliability and Dana's poor character judgement aren't a problem.
    - pwdisswordfish2 6y ago
      What if I already know "Carol"? Should a web browser block me from "conversing with Carol" because I did not get "Trent's" approval first? Seems like I should be the one who decides whether I approve of Carol or not. I am the one taking the risk of "having the conversation".