The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 17, 2002
Filed:
Jan. 08, 1999
Ioannis Milios, New York, NY (US);
Carl Oppedahl, New York, NY (US);
Usar Systems, Inc., New York, NY (US);
Abstract
A controller contains software which, when triggered in some prearranged way such as assertion of an input to the controller, calculates a digital signature for the contents of the protected memory of the controller. The digital signature is preferably extracted from the contents of the memory by means of a function that varies greatly with even small changes to the memory contents. The function preferably is such that one cannot easily determine from the output what input generated the output. The function is preferably such that one cannot easily create a data set for input that yields any particular predetermined output. The circuitry generating the signature may be embedded in hardware of the controller so that its digital signature function is unknown even to the programmer writing the main body of code to be stored in the protected memory. With such a hardware configuration, it is possible to have a very high degree of confidence that the memory contents are what they are expected to be.