Tolerance is the amount of variation in a component’s size, timing, voltage, or behavior that a system can handle before performance starts to suffer. In electronics, tight tolerances mean parts and traces must stay close to the intended design; looser tolerances increase the risk of signal loss, overheating, or unstable operation.
In cyber security, tolerance matters because attackers often exploit weak margins. Hardware with poor dimensional or electrical tolerance can be easier to disrupt through fault injection, environmental stress, or conditions that expose side channels. Defenders use tolerance-aware design, inspection, and testing to make devices more consistent and resilient. In PCB fabrication, tolerance helps determine whether a board is reliable enough for security-sensitive use or only suitable for rough prototyping.