Method and system for controlling certificate based open payment transactions

A system comprises:

• a programmable memory device associated with a user comprising an identifying certificate for identifying the user;
• a server;
• a computer connected to the server via a network, and comprising a processor configured to:
• present an amount due in response to a user's product selection;
• access a programmable memory device associated with the user, wherein the programmable memory device comprising an identifying certificate for identifying the user;
• retrieve the identifying certificate from the programmable memory device;
• generate a graphical user interface including one or more accounts to be debited;
• receive a selected account for payment of the amount due;
• attach transaction information including a deposit account to the identifying certificate and the selected account;
• sign the identifying certificate, the selected account, and the transaction information with a digital signature;
• transmit the identifying certificate, the selected account, the transaction information, and the digital signature to a server;
• and
• receive, from the server, an authorization message for payment authorization, wherein the server authorizes the payment by decrypting and authenticating the digital signature, authorizing the identifying certificate, and determining the selected account has sufficient funds to pay the amount due.