System and method for generating collison-free identifiers for financial transaction cards

摘要

A one-way permutation over financial transaction card data provides a merchant with a unique card identifier for each financial transaction card that is used by a customer to purchase goods from a merchant. This card identifier, which is not the actual financial transaction card data, may then be permissibly stored by the merchant and used to uniquely identify the customer's financial transaction card, and may also be used to determine the frequency with which that customer makes purchases using that card.