Abstract: A method including receiving, by a server computer, a request message from a token requestor computer on behalf of a user device. The request message comprising a first current token tracking value and a first function index value. The server computer can determine a second function index value. The server computer can then compare the first function index value to the second function index value. If the first function index value and the second function index value match, the server computer can determine a function based on the first function index value and a stored function table associated with the user device. The server computer can then determine a second current token tracking value based on the function, then compare the first current token tracking value to the second current token tracking value. The server computer can generate a response message in response to the comparing.

Abstract: A method including receiving, by a server computer, a request message from a token requestor computer on behalf of a user device. The request message comprising a first current token tracking value and a first function index value. The server computer can determine a second function index value. The server computer can then compare the first function index value to the second function index value. If the first function index value and the second function index value match, the server computer can determine a function based on the first function index value and a stored function table associated with the user device. The server computer can then determine a second current token tracking value based on the function, then compare the first current token tracking value to the second current token tracking value. The server computer can generate a response message in response to the comparing.

Abstract: A method including receiving, by a server computer, a request message from a token requestor computer on behalf of a user device. The request message comprising a first current token tracking value and a first function index value. The server computer can determine a second function index value. The server computer can then compare the first function index value to the second function index value. If the first function index value and the second function index value match, the server computer can determine a function based on the first function index value and a stored function table associated with the user device. The server computer can then determine a second current token tracking value based on the function, then compare the first current token tracking value to the second current token tracking value. The server computer can generate a response message in response to the comparing.

Abstract: A method including receiving, by a server computer, a request message from a token requestor computer on behalf of a user device. The request message comprising a first current token tracking value and a first function index value. The server computer can determine a second function index value. The server computer can then compare the first function index value to the second function index value. If the first function index value and the second function index value match, the server computer can determine a function based on the first function index value and a stored function table associated with the user device. The server computer can then determine a second current token tracking value based on the function, then compare the first current token tracking value to the second current token tracking value. The server computer can generate a response message in response to the comparing.

Abstract: Provided is a system for processing at least one merchant redemption voucher associated with a customer, including a transaction processing server having a processor programmed or configured to activate at least one merchant redemption voucher for use by the customer at a merchant based at least partially upon an activation request received from the customer, receive, from a merchant point-of-sale system, a transaction request associated with a transaction between the customer and the merchant and comprising a merchant identifier, a transaction amount, and an account identifier, identify the at least one merchant redemption voucher based at least partially on the account identifier, determine if the at least one merchant redemption voucher can be processed based at least partially on the at least one merchant redemption rule, and determine a modified transaction amount based at least partially on the transaction amount and the at least one merchant redemption rule.