Comment by cyphar

I think Moxie's "convergence" proposal from ~2011[1] has the most benefits with the least downsides -- in particular I think he really pointed out the crux of the issue: the fact that servers decide who is trustworthy enough to certify their certificates and clients have no input into that decision is a broken model.

This incident was obviously comically bad but the Comodo hack had a more painful impact on the mitigation that should give everyone pause -- their CA had signed a quarter of the internet's certificates so the trust couldn't just be revoked. Imagine one of the LetsEncrypt intermediates got compromised -- our mitigation strategies really cannot cope with that kind of disaster scenario. Browsers would be in the unenviable position where they'd be forced to make huge portions of the internet go dark for potentially months.

[1]: https://en.wikipedia.org/wiki/Convergence_(SSL)