Main Article Content
Industrial Control Systems (ICS) are using for monitoring and controlling process plants like Oil & Gas refineries, Power generation and distribution etc. The data acquisition server in these ICS systems uses communication protocol like MODBUS, DNP to collect the data from PLC (Programmable Logic Controller) or Remote Telemetry Unit (RTU). Currently, infrastructure utilities depend heavily on their ICS systems in real-time. In earlier days these ICS systems were isolated from the external world and used dedicated network. But as technology evolves and time passes, these systems are connected to internet for remote monitoring through web access and data transfer to higher layers like Enterprise Resource Planning (ERP). MODBUS is widely used communication protocol for bi-directional data transfer between PLC and SCADA Servers, in industrial control systems and have been using since long time. But there are no security measures in MODBUS protocol. Security of these national critical infrastructures is key important role in safe and secure operations of these plants. The communication protocols are one of critical areas where security vulnerabilities are predominant. In this paper a test bed was set up and various attacks were simulated and analyzed the impact of the various security vulnerabilities/attacks on MODBUS Protocol. We proposed a new method for enhancing the security in MODBUS protocol.