Research on the Network Security Protection Model of PLC Controllers for Industry 4.0

In the context of Industry 4.0, PLC controllers are the core components of industrial control systems (ICS), and their network security issues are becoming increasingly prominent. In response to this challenge, this paper proposes a network security protection model for PLC controllers for Industry 4.0. The model mainly combines access control with advanced encryption algorithms to achieve multi-level security protection for PLC controllers. Specifically, by designing an optimized encryption algorithm, the confidentiality and integrity of data during transmission are guaranteed, and at the same time, a role-based access control mechanism is introduced to effectively prevent unauthorized access and instruction execution. In addition, model simulation further verifies the effectiveness of the algorithm. The simulation results show that the model can effectively protect against a variety of attack scenarios, especially in dealing with man-in-the-middle attacks, denial of service attacks, and abuse of authority. It shows significant security and robustness. Accurate data analysis shows that compared with traditional protection methods, the model has increased the attack defense success rate by $15 \%$, while maintaining a low system resource occupancy rate, proving its application potential in actual industrial environments.