Hardening of the modbus protocol

Abstract

A large section of industrial control where network security is of paramount importance and where glitches can cause massive disruptions in societies has mostly been overlooked and ignored in recent times. Modern critical infrastructure assets (e.g., power plants, refineries and water supply systems) use ICT systems to provide reliable services and offer new features. Many maintenance and management operations at these installations involve the use of SCADA systems are controlled remotely using public networks, mostly over the Internet. While the automation and inter connectivity contribute to increased efficiency and reduced costs, they expose critical installations to new threats. Thus, issues relevant to the securing of this information when it's being transmitted via unsafe channels and unsecured protocols were chosen to be addressed. Various protocols that are used have either no provisions for secure transmission of its information or have outdated security structures. Our focus was on the Modbus protocol because of its wide application and lack of security features in the protocol structure. The objective was to establish a novel approach to the transmission via the Modbus protocol preserving the lower level attributes of transmission and at the same time adding a layer of security without adding significant delay.