Method of electronic payments that prevents double-spending

摘要

A method of generating electronic monetary tokens that supports off- line transactions while preventing double-spending. Generation of electronic token halves by a financial services provider begins in response to a request from a buyer to generate electronic monetary tokens to be used with an identified seller. First, the financial services provider generates a multiplicity of electronic monetary tokens. Second, the provider splits each electronic monetary token into two electronic token halves and associates with each the same serial number. These electronic token halves when combined recreate the electronic monetary token from which they were generated, but by themselves neither electronic token half has any value. Nor can either electronic half by itself be used to create the electronic monetary token without the token half's mate. After splitting all of the electronic monetary tokens, the services provider assigns a half of each electronic token the seller and the other half of each electronic token to the buyer. The buyer and seller can now engage in multiple transactions off-line of the financial services provider.