http://keybase5btp2qikoau6u326pvotn47gb55mo6fjxxyxdoywiinomr5id.onion/blog/keybase-proofs-for-mastodon-and-everyone
This new protocol change isn't just for Mastodon; we're ripping Keybase wide open, so any community can cryptographically connect profiles to Keybase. Everyone from a small phpBB forum to a big site such as Etsy, GitLab, or StackOverflow is welcome to do this easy integration.