Dynamic Watermarking for Compromised Sensor Detection in PV Grids
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The increasing number of sensors in power electronics devices in grid-tied photovoltaic systems due to distributed generation makes them vulnerable to cyber-attacks, necessitating a robust detection mechanism to protect these systems.
Innovation Solution
A dynamic watermarking approach is employed to inject a secret, stochastic signal into the control inputs of power conversion systems, which propagates through sensors, allowing for the detection of cyber-attacks via statistical variance tests.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the number of sensors in power electronics devices is increased to support distributed generation, then the capability to monitor and control power systems is improved, but the vulnerability to cyber-attacks increases
Solution Approach 1:
The system performs preliminary actions by injecting a watermark signal into the sensor measurements before they are used by the controller. This watermark signal serves as a pre-placed identifier that allows the system to later verify the authenticity of sensor readings and detect any unauthorized modifications, thereby preventing cyber-attacks rather than merely detecting them after occurrence.
Solution Approach 2:
The watermark signal acts as an intermediary element between the sensor and the controller. By embedding this unique signal into the measurement data stream, the system creates a verifiable chain of trust that mediates between the physical sensor output and the digital control system, enabling detection of any tampering or injection attacks.
2Device complexity
If traditional passive detection methods are used to identify compromised sensors, then the system complexity is kept low, but the detection capability against sophisticated cyber-attacks is insufficient
Solution Approach 1:
Rather than relying on complex post-detection analysis, the system performs preliminary action by embedding a watermark signal in advance. This approach simplifies the detection mechanism to a straightforward verification process: the system checks whether the watermark signal is present and intact in sensor readings, providing robust attack detection without requiring complex analytical algorithms.
Solution Approach 2:
The watermark signal acts as a unique identifier embedded in the sensor data stream, analogous to a visual watermark or signature. This embedded signal provides a clear, easily verifiable marker that distinguishes authentic measurements from compromised ones, enabling simple yet effective detection without complex system architecture.
Data Source
AI summary
Systems and methods for detecting compromised sensors using dynamic watermarking. In some examples, a method includes injecting a dynamic random signal into an input of a power distribution system. The power distribution system includes at least one sensor and at least one power electronic controller configured to use the at least one sensor. The method includes monitoring a sensor signal from the at least one sensor. The method includes determining whether the at least one sensor is compromised based on a comparison between the dynamic random signal and the sensor signal.