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Inventors: Robert H Nagel, et al

US patent number: 5,661,799

US patent application date: February 18, 1994
US patent issue date: August 26, 1997

SYNOPSIS OF THE INVENTION

This patent is based upon custom hardware including three CPU units, one of which contains a customized instruction set. This unit allows decryption for anyone of several million marketable digital items without the need for the use of inheritably flawed prior methods of key control. Accidental knowledge of any particular key gives no advantage as to how to determine additional keys on this unit or the key for the same marketable item on other units. This patent covers several practical inventions as well as a few generic inventions.