1. A method of providing access control on a mobile device, the method comprising: displaying an image on a touch screen of the mobile device; while the image is displayed on the touch screen, receiving user input from a user, the user input including user gestures applied to the touch screen over the displayed image; and 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; wherein performing the access control operation includes: outputting, as the access control result, a match signal indicating that the user input matches the expected input, and providing access to a set of access control keys in response to the match signal, each access control key being constructed and arranged to control access to a respective protected resource; and wherein receiving the user input from the user while the image is displayed over the touch screen includes: while a set of gridlines is rendered over the image, receiving a set of user gestures which trace over the set of gridlines rendered over the image, each gridline extending from one edge of the image to another edge of the image; wherein at least one user gesture traces along at least a portion of a particular gridline of the set of gridlines to copy that portion of the particular gridline; and wherein performing the access control operation which provides the access control result further includes: comparing the received set of user gestures which traced over the set of gridlines to an expected set of user gestures to determine whether the user is authentic.