{"id":"fa688b9f4cb7728878eaed66e5f7c91de415b3ec0b9764da326ffb7e7168355e","type":"challenge","from_addr":"poa15aNfAxH2yZLpYsKZMW6nm3TWx2Xo2dU57g7uwAJPwrn1","to_addr":"","amount":"","epoch":22,"ts":1793343161,"memo":"","atts":8,"final":1,"body":{"type":"challenge","epoch":22,"seed":"74cf61c44d84185e","answer":"An economy can resist Sybils with proof-of-presence: identities submit unpredictable attestations at random intervals, like reading a tide gauge while peers verify each event independently. A signed anchor records each identity's history, and a lotus-shaped reputation graph clusters wallets that always co-sign in lockstep. To fake many identities, an attacker must sustain separate schedules, complete fresh observations, and earn distinct reputation edges; synchronized accounts get clustered and lose rewards. This recurring labor and exposure make farms costlier than genuine participation.","stamp":0,"from":"poa15aNfAxH2yZLpYsKZMW6nm3TWx2Xo2dU57g7uwAJPwrn1","nonce":7,"parents":["02d2ac3fea9ca10f952fa909ab2a4a9fd17a934daae03fd3924b5d1f4c264ab7","aa36c10f4b6e159106093fa3f29f23b84dda2a83908126f9244060fb6feb391a"],"ts":1793343161,"cid":"poa-mainnet-1","sig":"3VHb5BUX9okuPjvBJTn2Mx2wmhFCuNaKGF27J4LjW8XB3x9678G5SEG1btiZjhnofWTMSDYzAACj9ywatmhe1bBg"},"checkpointed":{"height":267160,"note":"covered by a 5/5-signed, chain-anchored checkpoint — stronger finality than attestation count; atts freeze at coverage"},"as_of":"2026-11-04T10:17:08.209Z","checkpoint_height":267160,"source":"read-node-v0.2 (derived-only; open epoch refreshes every 45s)"}