US Patent 7822666 Secure single-use transaction numbers

Methods for producing and applications for single-use transaction numbers. The transaction numbers are single-use in that the numbers are only valid for a single transaction. The transaction numbers can be generated just prior to being used, minimizing the amount of time during which they can be lost or stolen. The transaction numbers can be generated using encryption technology such as dynamic password technology. The encryption technology makes it very difficult if not impossible to predict what the next transaction number generated will be. The transaction numbers are unique to the user and can be validated or authenticated by an issuing institution that maintains an ability to generate the same transaction numbers issued to the user.