System and methods for authenticating a transaction between a user system and a host system are described herein. In one embodiment, the system and methods use a text-reading test (TRT) image as part of the authentication process. The TRT image is presented to the user upon initiation of a transaction by the user. Information provided by a user, via the user system, after perception of the TRT image is compared to the source information in the TRT image. If the user input corresponds to the source information, the user is authenticated and transaction is allowed to proceed.