Human voices are individually recognizable because they’re generated by the unique components of each person’s voice box, pharynx, esophagus and other physical structures. Researchers at Georgia Tech are using the same principle to identify devices on electrical grid control networks, using their unique electronic “voices” fingerprints produced by the devices’ individual physical characteristics to determine which signals are legitimate and which signals might be from attackers. A similar approach could also be used to protect networked industrial control systems in oil and gas refineries, manufacturing facilities, wastewater treatment plants and other critical industrial systems.