convergence

Some pointers for you: - The Perspectives project (http://perspectives-project.org/) aimed to deploy a range of servers (called notaries), through which you can ask "What cert do you see for https://google.com ?", and compare the response. The idea was that certificates should be mostly the same wherever you're asking from. - Convergence (https://en.wikipedia.org/wiki/Convergence_(SSL)) is a fork of the same idea. The issue with both of them is, of course, privacy leaks, which the latest version of convergence (https://github.com/mk-fg/convergence#changes-from-upstream) solves with a custom onion routing. The other problem I see is that it still (in the current form) requires the user to manually edit the notaries list. So, it does exist, maybe it's just lacking publicity ?

There are some more active forks like https://github.com/mk-fg/convergence/ but they too seam to not really work in current versions of Firefox.

So convergence.io is only available over HTTP, yet it offers the plugin for download. It seems an ironically bad practice to install security software over an untrusted connection. Meanwhile, https://convergence.io yields a certificate for whispersystems.org and is in fact the https://whispersystems.org/ main page (nothing to do with convergence.io). There appears to be no secure way to obtain Moxie's plugin (it is not available from mozilla.org, though a fork is available, based on this repo: https://github.com/mk-fg/convergence). My understanding is that more recently, Moxie has been focusing on http://tack.io which offers improved security without overturning the CA model.