Kazi, Samreen BanuBronkar, Basheer [23DCO01]Sayyed, Mohammad Kaif [22CO42]Shaikh, Zaid [23DCO06]Patel, Ahmed [22CO38]2026-08-202026-08-202026-06http://aiktc.ndl.gov.in/handle/123456789/4566This project presents a multi-layered security enhancement for Industrial Control Systems (ICS) by hardening the OpenPLC platform against contemporary cyber-attacks. The primary objective is to address the inherent security deficits in legacy industrial protocols, such as Modbus/TCP and DNP3, which traditionally lack native authentication and encryption. To achieve this, we engineered an integrated security suite comprising Time- Based One-Time Password (TOTP) Multi-Factor Authentication for the web management interface, an automated vulnerability auditing tool for system boot-up, and TLS 1.3 encryption for data transit. The methodology further incorporates a real-time Intrusion Detection System (IDS) using Snort to perform Deep Packet Inspection (DPI), specifically targeting unauthorized industrial command injections. This objective was successfully achieved, resulting in a controller appliance capable of resisting sophisticated network-based threats. Experimental evaluations demonstrate that the proposed framework successfully identifies 98 percent of unauthorized industrial commands and completely mitigates credentialbased attacks. Significantly, the system maintains high operational efficiency by introducing a negligible latency overhead of less than 5 milliseconds, ensuring that the critical timing requirements of real-time industrial processes are never compromised.en-USProject Report