Decentralized Energy Resources (DERs) are small-scale power generation or storage technologies, such as solar panels, wind turbines, and battery systems, that are located close to where energy is used rather than at a large, central power plant. These resources can operate independently or be connected to the main electrical grid, providing flexibility, resilience, and efficiency. DERs play a crucial role in modern energy systems by enabling distributed generation, supporting renewable energy integration, and enhancing grid stability. However, their distributed nature also introduces new cybersecurity challenges, as each device can become a potential entry point for cyber threats if not properly secured.