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:
Jan. 14, 2003
Filed:
Dec. 30, 1999
Adi Shamir, Rehovot, IL;
Yeda Research and Development Co. Ltd., Rehovot, IL;
Abstract
A method and apparatus for protecting smart cards against simple and differential power attacks when they are inserted into card readers controlled by other entities. The technique is particularly useful in financial applications such as ATM cards, credit cards, and electronic wallets, in which cards have to be inserted into card readers which may be specifically manufactured or modified to perform undetectable measurements of the power supplied to the card during its normal operation. The basic technique is to use two capacitors embedded in the smart card in such a way that at any given time one of them is charged by the external power supply and the other one is discharged by powering the smart card chip. The roles of the two capacitors alternate rapidly, and the power supply is detached from the smart card chip in the sense that external power measurements do not reveal information about its internal operations.