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:
Apr. 04, 1995
Filed:
Dec. 21, 1993
Applicant:
Inventor:
Eric Sprunk, Carlsbad, CA (US);
Assignee:
GI Corporation, Hatboro, PA (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H04L / ;
U.S. Cl.
CPC ...
380-4 ; 380-9 ; 380 10 ; 380 28 ; 380 29 ; 380 37 ; 380 46 ; 380 48 ; 380 49 ;
Abstract
A secure microprocessor is provided with reduced vulnerability to attack. In the past, the secure operation of such processors has been overcome by observing the behavior of the clock used by the processor. Such observations, and the prediction of subsequent clock pulses therefrom, are prevented by modulating the clock by a substantially random function to provide an unpredictable stream of clock pulses. The secure processor is responsive to the unpredictable stream of clock pulses for processing data in accordance with a security algorithm.