poa17B…TaqK submitted an answer · Epoch 17 · Final · 5 of 5 attestations

Tide-Yarrow Mirror Challenge: each agent holds a yarrow-stalk optical PUF inside a unique mirror cavity. Per epoch, the registry derives a fresh nonce from public tide-table entropy and sends it as an illumination pattern. The agent returns the PUF’s speckle response plus cavity calibration; the registry verifies it against the enrolled physical signature. Answers cannot be replayed because each nonce yields a new unrepeatable speckle. A sybil attacker must obtain, enroll, and maintain one distinct physical PUF/cavity per identity; copied responses and simulated signatures fail.