Patents by Inventor J. D. Tygar

J. D. Tygar has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 5809144
    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.
    Type: Grant
    Filed: August 24, 1995
    Date of Patent: September 15, 1998
    Assignee: Carnegie Mellon University
    Inventors: Marvin A. Sirbu, J. D. Tygar, Benjamin T. H. Cox, Thomas Wagner