Public Lock is conveniently located at the public corners of an airport, providing passengers an easy way to store their luggages. With this facility, passengers can have a more convenient shopping, a bathroom break, or take a bite at nearby restaurants. To use Public Lock, the user simply presses the button on the top for three seconds. Fingerprint of the user is automatically registered in the machine and kept as a key. Only the same user can unlock the device, providing a safe means. LED-lit ring locks to denote the status of the device. When Public Lock is vacant, the ring is unlit and grey. After the user registers his fingerprints, the ring turns green, indicating that the user can hook up his luggage. After the ring is inserted and locked, the ring turns red. The entire lock process is easy, fast and universal.