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. 25, 2006
Filed:
Jul. 19, 2002
Helmut Horvat, Graz, AT;
Stefan Wallstab, München, DE;
Helmut Horvat, Graz, AT;
Stefan Wallstab, München, DE;
Infineon Technologies AG, Munich, DE;
Abstract
An integrated security circuit, for example, a microcontroller for smart cards, includes a function unit executing a security function. A control device determines the number of executions of the security function per unit of time. The continued execution of the security function is blocked when a threshold value is exceeded. For such a purpose, an analog timekeeper incorporating a charge storage device is preferably provided that measures the elapsing time even with the supply potential disconnected. A usage counter is updated whenever the security function is called. The security circuit offers increased protection against statistical attacks. The complexity involved in the implementation is justifiably low. The security circuit is compatible with the existing system.