http://keybase5btp2qikoau6u326pvotn47gb55mo6fjxxyxdoywiinomr5id.onion/blog/2015-07-15/keybase-raises-series-a
Why hasn't this been done already? Public key crypto is 40 years old. But two problems have prevented human adoption: confirming identity : how do you get public keys, safely & on-demand key management : most people don't understand what a "public key" is, let alone how to use one.