Time-to-bypass is the measured time it takes an attacker to defeat a protection, control, or guardrail during security testing. Instead of asking only whether a defense failed, this metric asks how quickly it failed under repeated pressure. A short time-to-bypass usually indicates a brittle control; a longer time suggests the attacker had to spend more effort finding a weakness.
In cyber security, time-to-bypass helps teams compare defenses that may look similar in a simple pass/fail test. It is useful in red teaming, prompt-injection testing, rate-limit evaluation, and other adversarial exercises where persistence matters. Defenders can use it to see whether changes make abuse harder, slower, or less reliable. For AI systems, it is especially helpful because a guardrail may block many obvious probes but still fall quickly to a targeted workflow attack or crafted input. Measuring time-to-bypass gives a clearer view of resilience than a single success rate.