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:
May. 04, 1999
Filed:
Nov. 04, 1996
Nippon Telegraph and Telephone Corp., Tokyo, JP;
Abstract
In an electronic cash implementing method using a trustee, a user registers his identification information ID.sub.U and anonymous public key N with the trustee and receives a license (B,I). The user processes the license (B,I) by a public key corresponding to the amount to be issued and sends the processed information to a bank to have it attach a blind signature to the information so that the user obtain electronic cash C from the blind signature. The user transmits to a shop the information B,I,C,N and a digital signature that assures the divisional use of the electronic cash. The shop verifies the validity of the information B and C and accepts it as cash and sends a history H of communication with the user to the bank and receives a payment therefrom. The bank places all received communication histories under its supervision and makes a check to see if the amount x spent by the electronic cash C is in excess of its face value X, and if so, informs the trustee of the information N contained in the communication history. The trustee uses the information ID.sub.U thus received to specify the corresponding user identification information ID.sub.U.