Electronic coin stick with potential for future added value

US6341273B1 · kind B1 · utility

Assignee

• BRITISH TELECOMMUNICATIONS public limited company · GB

Inventor

• Robert J Briscoe · London, GB

Key dates

• Filing date: Apr 29, 1998
• Grant date: Jan 22, 2002
• Expiry date: Apr 29, 2018

Classification

• Technology area (CPC G): Physics
• CPC primary: G07F7/1016
• WIPO field: IT methods for management
• WIPO sector: Electrical engineering

Abstract

In a digital payment transactions system, a broker generates and stores a secret number. The broker then generates a chain of hash values by successive operations of a hash function, using the secret number as the starting value. The broker then issues to the user a digitally encoded value from some way down the chain of hash values. The user generates a coin stick which comprises a chain of hash values starting with the value communicated by the broker. Subsequently, the broker can transfer further value to the user, without generating a new coin stick, by communicating a digitally encoded value from the broker's hash chain which precedes the value originally communicated to the user.