Everyday all around the world physical access control mechanisms are used to control who can go where and when. These systems often utilize a badge system that is flawed and vulnerable to abuse, or they incorporate biometric hardware that costs companies' tens of thousands of dollars. With GateKeeper we can lock down physical access points and require the user to authenticate using various methods with their local mobile device. Rather than having unfettered access to buildings, a smooth and fast authentication middleman can be added in to improve security, without greatly reducing costs.