Method and system for authorizing use of a transaction card

A method of operating a transaction processing data center for authorizing purchases by an owner of an account previously established with a data center, the owner wanting to purchase an item from a merchant, the method comprising the step(s) of:

• providing a plurality of authorization parameters available for use in calculating an authorization code associated with a specific transaction to purchase the item;
• receiving an input from the owner of a selected subset of the plurality of authorization parameters;
• receiving from the owner respective authorization parameter data for each of the selected authorization parameters;
• calculating the authorization code corresponding to the received respective authorization parameter data associated with said specific transaction;
• providing the authorization code associated with said specific transaction to the owner;
• providing the authorization code associated with said specific transaction to the merchant;
• receiving the authorization code associated with said specific transaction and transaction data from the merchant;
• calculating a confirmation authorization code from the transaction data corresponding to the received respective authorization parameter data;
• and
• comparing the authorization code associated with said specific transaction with the confirmation authorization code to determine whether or not to approve the transaction.

A system for authorizing purchases by an owner of an account previously established with a bank, the owner wanting to purchase an item from a merchant, the system comprising:

• means for providing a plurality of authorization parameters available for use in calculating an authorization code associated with a specific transaction to purchase the item;
• means for defining a selected subset of the plurality of authorization parameters;
• means for establishing respective authorization parameter data for each of the selected authorization parameters;
• means for calculating the authorization code corresponding to the established respective authorization parameter data associated with said specific transaction;
• means for providing the authorization code associated with said specific transaction to the owner;
• means for providing the authorization code associated with said specific transaction to the merchant;
• means for receiving the authorization code associated with said specific transaction and transaction data from the merchant at the bank;
• means for calculating a confirmation authorization code from the transaction data corresponding to the established respective authorization parameter data;
• and
• means for comparing the authorization code associated with said specific transaction with the confirmation authorization code to determine whether or not to approve the transaction.