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:
Sep. 24, 2013
Filed:
Jun. 26, 2008
Matthew Robshaw, Paris, FR;
Henri Gilbert, Bures sur Yvette, FR;
Marc Girault, Caen, FR;
Loic Juniot, Bougy, FR;
Matthew Robshaw, Paris, FR;
Henri Gilbert, Bures sur Yvette, FR;
Marc Girault, Caen, FR;
Loic Juniot, Bougy, FR;
France Telecom, Paris, FR;
Abstract
A system and a method for cryptographic reduced-coupon reloading are provided, where a coupon includes a pseudo-random number r=PRF(i), where i is an index for labeling the coupon, PRF is a predetermined pseudo-random function and K is a regeneration key, and a 'reduced-coupon' x=ƒ(r), where ƒ is a predetermined one-way function, where: a candidate device and a second device acquire a common value of a token T, the candidate device transmits a verification value vto the second device, the second device verifies whether the verification value is equal to PRF'(T), where PRF′ is a predetermined keyed pseudo-random function identical to, or derived from, the pseudo-random function PRF, where Q is an authentication key owned by the second device and known to the candidate device provided the candidate device is a legitimate reloading device, and if the verification is positive, one or several reduced-coupon(s) provided by the candidate device are stored in the second device.