Recently, the advancement of information and communication technology(ICT) is expanding the connectivity through Internet of Things(IoT), and the media of connection is also expanding from wire/cable transmission to broadband wireless communication, which has significantly improved mobility. This hyperconnectivity has become a key element of the fourth industrial revolution, whereas the supervisory control network of purification plants in korea is operated as a communication network separated from the outside, thereby lagging in terms of connectivity. This is considered the best way to ensure security, and thus there is hardly any consideration of establishing alternatives to operate an efficient and stable communication network. Moreover, security for management of a commercialized communication network and network management solution may be accompanied by immense costs, making it more difficult to make new attempts. Therefore, to improve the conditions for the current supervisory control network of purification plants, this study developed a industrial security L2 switch that supports modbus TCP(Transmission Control Protocol) communication and encryption function of the transmission section. As a result, the communication security performance improved significantly, and the cost for implementing the network management system using Historical Trend and information of HMI(Human Machine Interface) could be reduced by approximately KRW 200 million. The results of this study may be applied to systems for gas, electricity and social safety nets that are infrastructure communication networks that are similar to purification plants.

ABSTRACT
1. 서 론
2. 연구방법
    2.1 현 정수장 감시제어망의 구성과 취약점
    2.2 정수장 감시제어용 산업용 보안 L2스위치 개발
3. 결과 및 고찰
    3.1 정수장 감시제어망에서의 유해트래픽 차단 시험 결과
    3.2 이중화 및 재 연결 안정성 결과
    3.3 HMI 연동 시험결과
4. 결 론
References

• 김윤하(한국수자원공사 창원권지사) | Yunha Kim (Changwon Office, K-water)
• 유철(한국수자원공사 정읍권지사) | Chool Yu (Jeongeup Office, K-water)
• 오은(한국수자원공사 정보관리처) | Eun Oh (Management Information System Dept. K-water)
• 김찬문(한국수자원공사 정보관리처) | Chanmoon Kim (Management Information System Dept. K-water)
• 박익동(한드림넷 기술개발부) | Ikdong Park (Technology Development Dept. HanDreamnet Corporation)
• 김용성(경남대학교 바이오융합학부) | Yongseong Kim (School of Bioconvergence, Kyungnam University)
• 최현주(경남대학교 MSC교육부) | Hyunju Choi (Department of Mathematics Science and Computer(MSC), Kyungnam University) Corresponding author