Digital Watermark based Authentication for Intrusion Detection of Digital Substations

The paper proposes the use of digital watermark based authentication for intrusion detection in IEC 61850automated substations. The watermark can be embedded into the Least Significant Bits of the measurements without visible deterioration in precision. When Intelligent Electronics Devices gets measurements, the watermark in the measurement can be retrieved to determine whether it has been attacked and detect malicious intrusion. The proposed approach is appropriate for the time critical and resource constrained applications in substation automation system for its simplicity. Numerical simulation shows that the process latency and error incurred by watermarking is acceptable and will not impact performance of protective function in IEC 61850 automated substations.