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. 09, 1992
Filed:
Nov. 09, 1989
David M Claus, Indianapolis, IN (US);
Roy S Coutinho, Carmel, IN (US);
Kevin D Murphy, Indianapolis, IN (US);
James D Snavley, Greenwood, IN (US);
Kenneth R Zempol, Randolph, NJ (US);
AT&T Bell Laboratories, Murray Hill, NJ (US);
Abstract
An improved security system, including a protable smart card and a host computer, eliminates the need for the computer to store individual personal identification (ID) numbers for each user seeking access to the computer. Instead, the computer stores a first encryption algorithm E.sub.1 used in converting a particular identification number (ID).sub.n into a secret code S.sub.n for that particular user. S.sub.n also exists within the memory of the smart card having been loaded into its memory at the time of issue. A challenge number C is generated by the computer and transmitted to the smart card. Within the smart card and the computer, microprocessors respond to the challenge number C, the secret code S.sub.n, and a second encryption algorithm E.sub.2 in order to generate response numbers R.sub.n and R.sub.n ' respectively. Thereafter, R.sub.n is transmitted to the computer where it is compared with R.sub.n '. A favorable comparison is necessary for gaining access to the computer.