Method and apparatus for implementing electronic cash

US4977595A · kind A · utility

Assignee

• NIPPON TELEGRAPH AND TELEPHONE CORPORATION · JP

Inventors

• Kazuo Ohta · Zushi, JP
• Tatsuaki Okamoto · Musashino, JP

Key dates

• Filing date: Mar 28, 1990
• Grant date: Dec 11, 1990
• Expiry date: Mar 28, 2010

Classification

• Technology area (CPC H): Electricity
• CPC primary: H04L2209/56
• WIPO field: IT methods for management
• WIPO sector: Electrical engineering

Abstract

In an electronic cash implementing method, a user makes a bank apply a blind signature to user information Vi produced, by a one-way function, from secret information Si containing identification information, thereby obtaining signed user information. Further, the user makes the bank apply a blind signature to information containing authentication information Xi produced, by a one-way function, from random information Ri, thereby obtaining signed authentication information. The user uses an information group containing the signed user information, the signed authentication information, the user information and the authentication information, as electronic cash for payment to a shop. The shop verifies the validity of the signed user information and the signed authentication information, and produces and sends to the user an inquiry. In response to the inquiry the user produces a response Yi by using secret information and random information and sends it to the shop. Having verified the validity of the response the shop accepts the electronic cash.