SWITCH CONNECTION CONTROLLER FOR COMMUNICATION LINE

PROBLEM TO BE SOLVED: To enable flexible cooperation between an internal network and an external network while preventing a physical means from directly trespassing on the internal network, when accessing from the external network. SOLUTION: A security system, which prevents unauthorized infiltration to terminals and systems decentralized by purposes by see-saw type switching technology is provided by constituting a switch connection controller for communication lines, which is interposed between the communication lines and exclusively selects a connection with one communication line and a connection with the other communication line. Thus, the external network and internal network are disconnected by the see-saw type switching technology with a control signal of an access request corresponding to a purpose, so data can be protected securely against an unauthorized action.