Secure web-based monitoring and control system

Recently, we are often seeing more and more examples of Web-based Monitoring and Control System (WMCS) with the widespread use of the Internet technologies. In the Internet, however, systems or network services are subject to damage from various threats. In this paper, we discuss about a secure WMCS of which purpose and objective is to allow operation by authorized users via an intranet, while excluding unauthorized operation. A very important component to protect control network or devices in WMCS is a firewall that is called Plant FireWall (PEW). We propose main functions of PFW for securing the WMCS. nose functions are user authentication, operation right management, command filtering, progress report, communication path encryption, access log and format conversion.