US Patent 11757861 Prevention of token authentication replay attacks system and method

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.