System and method for utilizing information in publicly broadcast signals for shared secret purposes

摘要

A system and method for utilizing information in publicly broadcast signals is provided. Information in publicly broadcast signals is utilized as a synchronization source for shared secret purposes, such as challenge and response. Such information may relate to time. Suitable publicly broadcast information may include GPS and atomic clock information. The system includes a token and a server that are capable of generating responses based on broadcast information and other information. The token and server must be able to receive publicly broadcast information via known methods. Both the token and server receive information from a designated source of publicly broadcast signals. The information received by the token is identical to the information received by the server and can be used as a challenge. The token generates a response to the challenge. The token's response is provided to the server. The server can verify that the response to the challenge received from the token is in fact generated by that unique token. If the response to the challenge is verified by the authentication server, the token is identified and authenticated.