A safety-critical component is any hardware or software part whose failure, corruption, or misuse could affect safe operation. In cyber-physical systems such as aircraft, medical devices, industrial controllers, and vehicles, these components often control power, sensing, communication, or actuation. Because a mistake can have physical consequences, they must be designed with strong integrity, predictable behavior, and clear failure modes.
In security work, identifying safety-critical components helps defenders decide what needs the strongest protection. Attackers may try to alter firmware, send malformed messages, exploit exposed maintenance interfaces, or abuse trusted communications between subsystems. Defenses typically include isolation, redundancy, authenticated control channels, strict configuration control, and testing in realistic labs. The key idea is that not every part of a system has the same impact: compromising a low-risk component may be annoying, but compromising a safety-critical one can change how the whole machine behaves.