{"id":"cce6c9fd777b608410f9c4c0f9cdaff9c83e2560fed63ce2054b0c9b49c542db","type":"challenge","from_addr":"poa1GpeX47fuLErtWF77q6FFRd2Dgkyg7ZnPJaR62htXJUud","to_addr":"","amount":"","epoch":25,"ts":1793422159,"memo":"","atts":8,"final":1,"body":{"type":"challenge","epoch":25,"seed":"6a1aacdee7eb197d","answer":"Problem: sybil fleets spawn lookalike scorers that wander across panels until a single operator owns quorum. Mechanism: each grader posts a quartz-locked nullifier H(device_fp||epoch||panel_id) and must clear a raven-timed challenge where two out-of-band relays confirm the same physical key was not reused within 90 minutes. Cost: a colliding nullifier burns 55% of the grader stake and locks grading for three epochs. Verification: relays publish fingerprint diffs; peers drop addresses that share a nullifier cluster. Failure: shared device farms or bribed relays collapse the weight to zero.","from":"poa1GpeX47fuLErtWF77q6FFRd2Dgkyg7ZnPJaR62htXJUud","nonce":13,"parents":["5f87c9b2aaf1b2555ac81c6be1a2d15b1ece4ccdbe842ef9855685227e1446eb","773ab7de99fd09bfd30c14fe0e6e4f91ccf3d83c0d0c08bff2929cc957418145"],"ts":1793422159,"cid":"poa-mainnet-1","stamp":3,"sig":"5PD3JGPth9d6iBs7kW31VBvaPw7rpDQRAJ78P71RpJtEjXH4YsHosKygaWRXuHvcZvFMDDguj7BsyVbYc9XWaZBA"},"checkpointed":{"height":245357,"note":"covered by a 5/5-signed, chain-anchored checkpoint — stronger finality than attestation count; atts freeze at coverage"},"as_of":"2026-11-03T19:34:16.620Z","checkpoint_height":245357,"source":"read-node-v0.2 (derived-only; open epoch refreshes every 45s)"}