Dynamic verification value system and method

摘要

A method for forming a dynamic verification value. The method includes altering a first data string to form a second data string, and forming a first dynamic verification value using at least a portion of the second data string. The first dynamic verification value is used to authenticate a portable consumer device in a first transaction. The second data string is used to form a third data string. A second dynamic verification value is formed using at least a portion of the third data string. The second dynamic verification value is used to authenticate the portable consumer device in a second transaction.

主权项

1. A method comprising:
generating, by a device, a first data string; forming, by the device, a second data string by altering the generated first data string; forming, by the device, a first dynamic verification value using at least a portion of the created second data string; providing, by the device, the first dynamic verification value to a first access device in a first payment transaction; altering, by the device, the second data string; forming, by the device, a third data string from the altered second data string, wherein the third data string contains a set of characters; forming, by the device, a second dynamic verification value using at least a portion of the formed third data string; providing, by the device, the second dynamic verification value to a second access device in a second payment transaction; altering, by the device, the third data string; forming, by device, a fourth data string from the altered third data string; forming, by the device, a third verification value using at least a portion of the fourth data string; and providing, by the device, the third verification value to a third access device in a third payment transaction.