Reaction-time gate answered faster than the human physiological floor (or before the go cue)
bh.arena_reaction_superhuman · convicts
What it catches
Kitsune arena REACTION-TIME gate (arena/reaction.go) — a 'click when the box turns green' reaction check (used in anti-bot / game flows), reproduced as owned infra. The gate mints a random pre-cue delay; the box turns 'go' after it, and the client clicks. The SERVER derives the reaction latency = the server-observed age (mint->verify) MINUS the shown delay — both server-clocked, so the client's clock is not trusted. TELL: a reaction below reactionFloorMs (120ms) is superhuman. The human SIMPLE VISUAL REACTION floor is ~150ms (elite ~150-200ms, average ~250ms); no human hand-eye loop responds to an unpredictable visual change in under 120ms, and a NEGATIVE reaction (a click reaching the server before the go time) is anticipation — a bot that clicks the instant it computes the cue, or pre-fires. anomaly:reaction_superhuman -> the detector relay (/arena/reaction/verify) joins it to ks_sid so the SESSION convicts on coherence (the gate fails for the bot, like honeypot, and the anomaly rides the verdict). A NEW tell family — REACTION LATENCY against a physiological floor — distinct from the solve-speed / precision / plan tells of the other gates. FP-SAFE BY CONSTRUCTION: the floor sits below even elite human reaction with network margin, so a genuine human always exceeds it and passes silently; unforgeable in the too-fast/anticipation direction (a bot cannot react SLOWER than instant without paying the human-reaction cost, which is the arena point). EXPERIMENTAL (w0.85, calibration: the RED evader that adds a ~250ms human-like reaction delay before clicking evades — but pays the latency, and the greedy speed-optimising bot is caught; a click before the go is always impossible). GROUNDED LIVE BOTH DIRECTIONS: an instant click (reaction ~5ms) and an anticipatory pre-go click (negative) convict; a human-plausible ~260ms reaction is silent.
Signals it reads
behavioral.arena_reaction_superhuman
How it fires
present
Bypassed by 10
Frontier evaders that reach the detector uncaught (scored only suspicious, defeating every convicting tell) — this check is not one that stops them. The red-team frontier this detection still has to convict.