Inventors:
Marvin A. Sirbu - Pittsburgh PA
J. D. Tygar - Pittsburgh PA
Benjamin T. H. Cox - Pittsburgh PA
Thomas Wagner - Pittsburgh PA
Assignee:
Carnegie Mellon University - Pittsburgh PA
International Classification:
H04L 900
Abstract:
A method for purchasing and delivering goods over a network is comprised of the steps of identifying a digital good to be purchased. A purchase price for the digital good is negotiated. After the negotiation step, an authenticated purchase request is sent to the merchant. The merchant encrypts the desired digital good and calculates a first cryptographic checksum for the encrypted good. The encrypted digital good and the first cryptographic checksum together with a timestamp are then transmitted to the customer. The customer calculates a second cryptographic checksum for the received encrypted digital good. The customer creates an electronic payment order containing information identifying the transaction, the second cryptographic checksum, credentials, and the timestamp. The electronic payment order is transmitted to the merchant. The merchant compares the first and second cryptographic checksums to ensure that they match, and if so, the merchant adds an electronic signature and a decryption key to the electronic payment order.