Abstract: The embodiments presented within provide methods, devices, and systems that improve access control through the use of smart cylinder locks. In one embodiment, a smart cylinder may perform a process including receiving a key, emitting an energy source of electromagnetic radiation; detecting a change in the energy source due to a physical property of the key, determining the physical property of the key from the change in the energy source, comparing the physical property with a predetermined value, and engaging a mechanism operatively coupled to a locking device that allows the locking device to lock or unlock when the physical property matches the predetermined value.