1. A method for secure document delivery from a sender over a wide area network, comprising the steps of: a sender encrypting a document using a secret key; the sender contacting a Delivery Server to query a public key associated with an intended recipient; the Delivery Server dynamically retrieving the public key in real time from a certificate authority; the Delivery Server transmitting the public key back to the sender; the sender encrypting the secret key with the public key; and the sender transmitting the encrypted document and the encrypted secret key to the Delivery Server for transmission to the recipient.