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:
Mar. 30, 1999
Filed:
Jul. 15, 1996
Kazuo Ohta, Zushi, JP;
Eiichiro Fujisaki, Yokosuka, JP;
Atsushi Fujioka, Yokohama, JP;
Masayuki Abe, Yokohama, JP;
Nippon Telegraph and Telephone Corporation, Tokyo, JP;
Abstract
In a method for implementing traceable electronic cash, a user US sends a bank BK a product N of prime numbers P and Q, a prime number L and his real name ID.sub.U, and the bank BK generates a pseudonym I corresponding to the real name ID.sub.U and keeps the correspondence between the real name ID.sub.U and the pseudonym I secret. The bank BK uses a signature function .OMEGA.=D.sub.eB (N,L,I) to attach a signature to information composed of the above-mentioned N, L and I and sends the user US the signed information .OMEGA. as information containing a license B. The user US generates authentication information X from the N and a random number R and sends the bank BK information Z obtained by performing blind signature preprocessing on information (X,B) with a function F.sub.eC and has the information Z signed by the bank BK with a signature function D.sub.eC (Z) to obtain electronic cash C. When the user US abuses the electronic cash C, the bank BK follows a court order to reveal the correspondence between the real name ID.sub.U and pseudo name of the user US and trace the electronic cash spent.