Data diode device with specific packet relay function, and method for specifying same

Abstract

A data diode device with specific packet relay function () is connected between an external network and an internal network. The data diode device with specific packet relay function () includes a first unit () and a second unit () connected by a signal line (Q), and the first unit () connected with the external network () has a first reference table (T) in which a plurality of pieces of packet registration information are registered to correspond to the signal lines (Q). The second unit () connected with the internal network () has a second reference table (T) content of which is the same as the first reference table (T). By activating the signal line corresponding to the packet registration information including a source IP address, a destination IP address and application data which are included in a packet received by the first unit (), the content of the packet and that the packet to be transmitted to the internal network () is received are conveyed to the second unit (). The second unit () generates the packet based on the packet registration information to deliver to the second network. The data diode device with specific packet relay function () relays the packet from the internal computer () to the external computer () by use of a unidirectional transmission path S for transmitting data in one direction.