| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To block the invasion of illegal communication data from one network into the other network even if the illegal communication data invade into a gateway. <P>SOLUTION: A non-secure network gateway 11 and a secure network gateway 12 are obtained by mutually independent computers and connected to a non-secure network 1 and a secure network 2 using standardized standard protocols and whose specifications are opened by standard protocol communication parts 20, 25. Between non-standard protocol communication parts 22, 23 of the respective sub-gateways 11, 12, data transfer is performed using non-standard protocols whose specifications are not opened and data transfer between the non-standard side and the standard side is performed only by an application layer. Protocol conversion parts 21, 24 check the relay permission of the communication data by referring to relay permission setting tables 30, 31 and only when there is the relay permission, perform protocol conversion. <P>COPYRIGHT: (C)2007,JPO&INPIT</p> |
