A Lightweight Entity and Command Authentication Protocol for Smart Grid

Industrial Control Systems (ICS) play a vital role in critical infrastructure operations such as power generation, water treatment, and manufacturing, where even slight disruptions can result in serious impacts on safety, efficiency, and national security. With the advent of Industry 4.0 and smart grid technologies, ICS are becoming more interconnected with corporate and external networks, thereby increasing exposure to cyber threats and revealing weaknesses in outdated communication protocols. Among these protocols, Modbus remains one of the most commonly used due to its simplicity, ease of deployment, and compatibility with existing equipment. However, its lack of built-in security mechanisms, such as encryption and authentication renders it highly susceptible to attacks, particularly in smart grid contexts where reliable and secure real-time communication is essential. This paper examines how Merkle tree-based authentication techniques can strengthen Modbus communication security by safeguarding data integrity and authenticity. As a lightweight yet powerful cryptographic structure, Merkle trees are well-suited for the resource-constrained nature of ICS environments. The study further reviews current approaches, highlights their strengths and weaknesses, and proposes enhancements aimed at striking an optimal balance between system performance and robust security in industrial settings.