Abstract: A system and method for transferring an encrypted file over the Internet involves a seller, a buyer, and a transaction agent. The file has a first part (administrative information) and a second part (subject-matter content) that are respectively encrypted with first and second encryption/decryption non-public keys. In operation, the appropriate key is released by the seller or the transaction agent for respective use by either the transaction agent or the buyer, to decrypt and reveal the second part of the file to the buyer.

Abstract: A system and method for transferring an encrypted file over the Internet involves a seller, a buyer, and a transaction agent. First, the seller creates a file for publication on the Internet. This file has, at least, an overhead part that is encrypted with a public key provided by the transaction agent, and it has a content part that is encrypted with a private key provided by the seller. In operation, the buyer selects the desired file from the Internet and sends its overhead part to the transaction agent for decryption. The decryption is then done using the public key to ascertain the private key. Subsequently, the private key is used, either by the transaction agent or by the buyer, to decrypt and reveal the content part of the file from the Internet for use by the buyer.