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. 29, 1993
Filed:
Jun. 08, 1992
Tatsuaki Okamoto, Yokosuka, JP;
Kazuo Ohta, Zushi, JP;
Nippon Telegraph and Telephone Corporation, Tokyo, JP;
Abstract
In an electronic cash system, K sets of blind signature information are derived from secret information containing identification information of a user, K/2 sets of them are opened and a bank attaches a blind signature to the remaining K/2 sets of information. The user obtains a signed license from the blind signature. The user generates blind signature information from the license and a desired amount of money and gets a blind signature of the bank to the blind signature information and obtains electronic cash signed by the bank from the blind signature. The user presents to a shop a residue power root of a node in a money hierarchial structure and the electronic cash, corresponding to the amount of money to be used, and the shop verifies their validity and, if they are valid, offers inquiry information to the user. The user offers, as response information, a residue power root of the node corresponding to the amount of money to be used to the shop. The shop verifies the validity of the response information and, if it is valid, acknowledges the payment with electronic cash of the amount of money to be used.