OpenPGP / PGP Key Robot Certificate Authorities
Robot certificate authorities (CAs) sign any PGP key you submit and verify that the email address is yours. If a key is signed by a robot CA, you can be sure it does belong to the email address it pretends to belong to.
Robot CA at toehold
The robot certificate authority signs any PGP key and returns it to the email address listed in the key. Keys can be submitted via email or via a Web interface.