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:
Jun. 23, 1998
Filed:
Aug. 01, 1996
James E Gilley, Lincoln, NE (US);
Kenneth L Snyder, Elmwood, NE (US);
Paul A Schwartzkopf, Lincoln, NE (US);
Transcrypt International, Inc., Lincoln, NE (US);
Abstract
An apparatus and method for controlling the feature set of a programmable device by assigning each programmable device a unique serial number, correlating a secret key with each serial number, and keeping that information in a secure location, such as at the manufacturer. Each optional feature set for the programmable devices is assigned a unique code, and software associated with the programmable device operates according to the feature set identified in the feature set code, if an authentication procedure is passed. The authentication procedure utilizes a secure cryptographic algorithm to calculate an authentication code based on the secret key and the authorized feature set for a programmable device. The authentication code is stored in the programmable device. Periodically, the programmable device automatically self checks itself by recalculating the authentication code. If it matches with the authorized authentication code, the authentication procedure is passed. If it does not match, the authentication procedure is not passed as it tends to indicate that there has been an attempt to tamper with the feature set code or to use an authorization code that is from another programmable device. If the authentication procedure is not passed, the programmable device may be disabled or some other limitation may be imposed on the device.