Analog redundancy is a backup control or monitoring path built from non-digital components, such as relays, switches, gauges, or hardwired circuits, that can keep a system functioning if software, firmware, or networked controllers fail. In industrial and critical infrastructure settings, it gives operators an alternate way to observe conditions or execute essential actions when digital systems are unavailable or untrusted.
In cyber security, analog redundancy matters because attackers often aim at the digital layer first: they may compromise a PLC, disrupt a SCADA network, or disable sensors and automation. A separate analog path can reduce the blast radius by preserving basic control, shutdown, or override capability even during a cyber event. Defenders use it as part of secure-by-design and resilience engineering, especially for safety-critical processes. It is not a substitute for good security, but it can make compromise less likely to turn into physical damage or unsafe operation.