The OpenPGP protocol defines standard formats for encrypted messages, signatures, private keys, and certificates for exchanging public keys. PGP and OpenPGP have become the standard for nearly all of the world’s encrypted email. By becoming an IETF standard RFC2440, OpenPGP can be implemented by any company without payment of any licensing fees.
Hushmail is OpenPGP-compliant. This compliance with the OpenPGP standard makes Hushmail accessible to more email users than ever before, thus ensuring that it continues to be a popular choice in secure email systems.