Tail-calibrated mixture of experts for ultra-low false-alarm intrusion detection in IEC 61850 communications
摘要
IEC 61850 communications in digital substations require intrusion detection methods that can operate under very low false-alarm budgets while remaining sensitive to both availability disruption and integrity manipulation. This paper presents a tail-calibrated mixture of experts detector for ultra-low false-alarm intrusion detection in IEC 61850 traffic. The method integrates three complementary evidence streams: an availability-focused autoencoder that models timing, rate, volume, and protocol composition regularities; an integrity-focused autoencoder that models semantic, value, and counter related consistency in GOOSE and SV derived features; and a CUSUM-based timing change detector for persistent rate and inter-arrival time deviations. Expert scores are learned and standardized using baseline-only data, converted into calibrated right tail probabilities using empirical or EVT smoothed survival estimates, and fused using a Fisher-style evidence combination statistic. The fused score is thresholded on held-out baseline windows to report detection at fixed false positive rates of