Data protection method for computer network by assigning control units which prevent additional connections outside network when computer is in use within network

摘要

A computer functioning as a communications controller in the computer network is assigned a control unit which prevents the computer from supporting addition connections outside the network whenever it is in use within the network. The external connection may be a connection to a second computer network such as the Internet via a modem. The control unit is responsive to the operating voltage in the control unit, which may be manually switched or controlled by a time switch. An apparatus for performing the method is also claimed.