2 ms·

The basis of the PGP/GPG approach is in-person key signing. It can only work if you're willing to authenticate somebody's identity with them face-to-face (keep

The basis of the PGP/GPG approach is in-person key signing. It can only work if you're willing to authenticate somebody's identity with them face-to-face (keep in mind that publishing your public key online is currently only possible because of CAs). That depends on what you're trying to prove. At the moment, CAs typically accept that someone attempting to create a certificate for a certain domain is the legitimate owner if that person can demonstrate immediate control over something like the content of the website or the DNS. Attempts to enforce stronger verification, such as EV certificates, have largely fallen flat. An equivalent standard would be no worse as the basis for a web of trust system than it is as a basis for major CAs issuing certificates today. The biggest problem with today's CA system isn't that there are trusted authorities, it's that for any given cert there is one and only one ultimate trusted authority and if there are further certs involved then the dependency chain is strictly linear. This creates both gatekeepers and single points of failure. A system where multiple reputable sources could indicate their trust in a certain identity and where authentication was based on looking for multiple trusted paths to verify a claimed identity would address several of the practical weaknesses of our current CA-based infrastructure.

AmericanChopper 6y ago
Having your certificate signed one time or three times or a hundred times doesn’t really change the dynamics of the problem at all. Without an authority you put the burden of authentication on the user (no matter what ceremony they use). This fact alone makes it a generally useless approach to PKI. The only thing the web of trust does is allow you to share that burden with a select number of people that you actually know and trust. If you try to extend the perimeter of the web beyond that, it just becomes a web of horribly misplaced trust. Reframing it as a web of reputation doesn’t change anything either.
- Silhouette 6y ago
  Having your certificate signed one time or three times or a hundred times doesn’t really change the dynamics of the problem at all. Just to clarify, I'm not necessarily talking anything as specific as signing a certificate. I'm talking about the problem of authentication in general, whatever mechanism it might use. Maybe we're talking at cross-purposes as I'm not sure exactly what problem you're trying to solve here, but my argument is that the main problem with existing CAs is that they represent single points of failure in several respects. Authenticating against multiple sources from a potentially larger pool does then change the dynamics in exactly two very important ways: it means neither the site host nor the site visitor is reliant on a single CA and thus a single potential point of failure any longer. This isn't a complete solution to all possible problems with the existing CA system, but it does offer a conceivable way to mitigate some known weaknesses in that system. Getting that far doesn't really even need a full web of trust system, just a mechanism for seeking confirmation from N of M ultimate authorities where N is chosen such that 1 < N < M with whatever safety margin on either end you deem appropriate. But a more comprehensive web of trust would potentially allow for a fully decentralised system in the sense that anyone could operate their own final authority but how much it was trusted would depend on the properties of the web (as would how much any default authorities included with browsers as standard were or potentially were not to be trusted).
  - AmericanChopper 6y ago
    What you’re describing is not a known weakness in the CA system, and doesn’t even really touch on the actual known issues with implementing PKI. The CA is not a point of failure. If one CA fails to sign your certificate, you just get one from a different CA. If a CA that had already signed your certificate vanishes, nothing fails because your existing certificates do not suddenly become unsigned. The core issues with PKI are establishing trust. The only way to do that for most applications requires an authority. You’re not improving the system by requiring multiple authorities to sign every certificate. You’re not making things less authority-reliant or more resilient. You’re just making it more complicated, and leaving the real underlying issues around authentication unchanged.

AmericanChopper 6y ago

Having your certificate signed one time or three times or a hundred times doesn’t really change the dynamics of the problem at all. Without an authority you put the burden of authentication on the user (no matter what ceremony they use). This fact alone makes it a generally useless approach to PKI. The only thing the web of trust does is allow you to share that burden with a select number of people that you actually know and trust. If you try to extend the perimeter of the web beyond that, it just becomes a web of horribly misplaced trust. Reframing it as a web of reputation doesn’t change anything either.

Silhouette 6y ago
Having your certificate signed one time or three times or a hundred times doesn’t really change the dynamics of the problem at all. Just to clarify, I'm not necessarily talking anything as specific as signing a certificate. I'm talking about the problem of authentication in general, whatever mechanism it might use. Maybe we're talking at cross-purposes as I'm not sure exactly what problem you're trying to solve here, but my argument is that the main problem with existing CAs is that they represent single points of failure in several respects. Authenticating against multiple sources from a potentially larger pool does then change the dynamics in exactly two very important ways: it means neither the site host nor the site visitor is reliant on a single CA and thus a single potential point of failure any longer. This isn't a complete solution to all possible problems with the existing CA system, but it does offer a conceivable way to mitigate some known weaknesses in that system. Getting that far doesn't really even need a full web of trust system, just a mechanism for seeking confirmation from N of M ultimate authorities where N is chosen such that 1 < N < M with whatever safety margin on either end you deem appropriate. But a more comprehensive web of trust would potentially allow for a fully decentralised system in the sense that anyone could operate their own final authority but how much it was trusted would depend on the properties of the web (as would how much any default authorities included with browsers as standard were or potentially were not to be trusted).
- AmericanChopper 6y ago
  What you’re describing is not a known weakness in the CA system, and doesn’t even really touch on the actual known issues with implementing PKI. The CA is not a point of failure. If one CA fails to sign your certificate, you just get one from a different CA. If a CA that had already signed your certificate vanishes, nothing fails because your existing certificates do not suddenly become unsigned. The core issues with PKI are establishing trust. The only way to do that for most applications requires an authority. You’re not improving the system by requiring multiple authorities to sign every certificate. You’re not making things less authority-reliant or more resilient. You’re just making it more complicated, and leaving the real underlying issues around authentication unchanged.