The Cypher Locks from Continental Instruments are a hack-proof access control system that are used extensively on ships and in government offices around the world. The vandal resistant keypads are connected to the controller via a 10 conductor wire and codes are changed by physically plugging the different conductors into the controller in a certain order. Because these controllers are not connected to a network and are not programmed via computer it is impossible to compromise without having physical access to the controller, which is installed on the secure side of the door.
This page has good information about the Cypher Lock, which can be tough to come by, and Group One has been helping customers determine the right Cypher Lock for their application for years. E-mail us or give us a call at 425.454.9900 and we will be happy to walk you through your need.