A system is provided that allows users to communicate securely. A key management service may generate a single public-key/private-key pair. A sender who desires to send a secure message to a receiver may encrypt the message using a message key. The sender may use the public key to encrypt the message...http://www.google.se/patents/US7412059?utm_source=gb-gplus-sharePatent US7412059 - Public-key encryption system
