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. 02, 1998
Filed:
Jul. 18, 1996
Robert Naciri, Chatenay Malabry, FR;
De La Rue Cartes ET Systemes SAS, Paris, FR;
Abstract
The procedure involves key numbers 'd' and 'e' and a modulus N, so hat 'N' is the product of two factors 'p' and 'q' which are prime numbers N=p.q, and e.d=1.sub.MOD.phi.(N), where .phi.(N) is the Euler indicator function. The procedure provides enciphered message parts and for deciphering them comprises: a modulus-determining step for determining a deciphering modulus chosen from 'p' and 'q', a modular reduction step for making a first modular reduction of the number 'd' with a modulus equal to said deciphering modulus '(p-1),(q-1)' with the aim of producing a reduced number, a reduction step for making a second modular reduction of each enciphered message part with a modulus equal to said deciphering modulus with the aim of producing a reduced enciphered message part, an exponentiation step for computing a modular exponentiation of each reduced enciphered message part with a modulus equal to said deciphering modulus and with an exponent equal to said reduced number with the aim of restoring said message.