Disclosed is a method and system for preventing replay attacks for mobile promotions associated with gaming devices. Upon the occurrence of a promotion winning event such as a designated outcome of a game played on the gaming device the user, via a software application accessible to their mobile device, forwards images of the event to a server over a network. The server determines entitlement to the promotion and analyzes data associated with the images and mobile device location and time to confirm that the event is new promotion winning event. Upon such confirmation an entitlement to the promotion is awarded to the user. The foregoing prevents unscrupulous users from logging multiple claims for the same promotion winning event.