Methods and apparatus for creating and storing secure customer receipts on smart cards

A method for creating authenticated electronic retail transaction receipts by generating a retail merchant'signature, the method comprising the steps of:

• storing data in a computer memory, said data comprising a retail merchant identification number, a retail customer identification number, and transaction data;
• generating a transaction specific session key;
• encrypting said data with the transaction specific session key to generate a merchant signature;
• generating a record comprising said merchant signature and detailed transaction data;
• and
• storing the record on a point of sale (POS) system.

A method for processing a returned retail purchase comprising the steps of:

• reading retail transaction data from a memory of customer secure medium, said retail transaction data including a retail merchant identification number and a retail customer identification number;
• reading a merchant signature associated with said retail transaction data from the memory of the customer secure medium;
• reading a merchant signature key from a merchant secure medium;
• encrypting said retail transaction data with the merchant signature key to generate a generated merchant signature;
• and
• comparing said merchant signature read from a customer secure medium to said generated merchant signature to the authenticity of said retail transaction data.

A system for generating and storing verifiable electronic retail transaction receipts comprising:

• a point of sale (POS) system including a plurality of POS terminals, said terminals comprising a microprocessor, a memory, an operator keyboard, an operator display, a cash drawer;
• a store controller;
• a computer program executed by the POS system for storing data in the memory comprising a retail merchant identification number, a retail customer identification number, and transaction data, said program for encrypting said data with a merchant supplied signature key to generate a merchant signature and generating a verifiable electronic retail transaction receipt comprising said merchant signature and detailed transaction data;
• and
• a customer secure medium and a merchant secure medium for storing said verifiable electronic retail transaction receipts.

A method for creating authenticated electronic retail transaction receipts by generating a retail merchant's signature, the method comprising the steps of:

• storing data in a computer memory, said data comprising a retail record having at least one element related to a transaction;
• storing in a computer memory a merchant supplied signature key;
• encrypting said data with the merchant supplied signature key to generate a merchant signature;
• generating a record comprising said merchant signature and detailed transaction data related to the transaction;
• and
• storing the record on a point of sale (POS) system.