Abstract: A system for verifying and authenticating the identity of a user in a transaction. The user's identity is authenticated through the user's computer, tablet computer, mobile computing device, web browser (as a web-page, or as a plug-in for the browser), or other computing device by means of a single-use, time sensitive, system-generated transaction token and user selected system PIN. The user presents the transaction token to the vendor or merchant, which forwards a request for authentication to the system. The system prompts the user to confirm the transaction and enter the PIN into the device used to generate the transaction token. Upon confirmation, the transaction is completed.