ACCESS CONTROL BY A MOBILE DEVICE USING AN IMAGE

A technique provides access control on a mobile device (e.g., a smart phone, a tablet, etc.). The technique involves displaying an image on a touch screen of the mobile device. The technique further involves, while the image is displayed on the touch screen, receiving user input from a user. The user input includes user gestures applied to the touch screen over the displayed image. The technique further involves performing an access control operation which provides an access control result based on the user input, the access control result (i) providing access to a set of protected resources when the user input matches expected input and (ii) denying access to the set of protected resources when the user input does not match the expected input.