Patents by Inventor William Frezza

William Frezza 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).

  • Security arrangement for downloadable cable television converters
    Patent number: 4712239
    Abstract: A method and apparatus prevent unauthorized programming viewing via a downloadable cable television converter. A booter checksum is computed from data contained in a downloaded booter image. A valid checksum is extracted from tag data associated with a scrambled program signal transmitted on the cable system. The booter checksum is compared to the extracted valid checksum. If the booter checksum and valid checksums match, a descrambler is enabled to descramble the scrambled program signal. If the checksums do not match, the descrambler is not enabled. In this manner, a pirate is prevented from downloading a false booter image to defeat the integrity of the converter.
    Type: Grant
    Filed: June 16, 1986
    Date of Patent: December 8, 1987
    Assignee: General Instrument Corporation
    Inventors: William Frezza, Robert Simons, Richard Westerfer