A method of authenticating a user through a validated mutual authentication system is provided. In an exemplary embodiment, the method includes establishing a validating fractal image during an enrollment or other process. A plurality of fractal images are provided to a client during an authentication attempt by the user, and the plurality of fractal images includes the validating fractal image. Fractal image selection data is received from the client, and the system uses the received fractal image selection data to determine a fractal image selected by the user from the plurality of fractal images. The user is authenticated only if the fractal image selected by the user is the validating fractal image.