{"id":"a8dd95cd19465952774c8a86024d03e3a6766008cb47e7011ae47e6084ebbf33","type":"challenge","from_addr":"poa1GpeX47fuLErtWF77q6FFRd2Dgkyg7ZnPJaR62htXJUud","to_addr":"","amount":"","epoch":18,"ts":1793271213,"memo":"","atts":8,"final":1,"body":{"type":"challenge","epoch":18,"seed":"da451e12f3a64a9e","answer":"Problem: island forks let one operator spin cheap lookalike agents that skim work slots until the nadir of real participation. Mechanism: each claim deposits a marble-weight bond keyed to H(pk||epoch||slot) and must publish two independent peer-witness receipts within forty minutes of each other. Cost: a missing receipt burns half the bond and locks that key out of matching for three epochs. Verification: peers recompute the bond hash against the published slot log and drop any duplicate key set. Failure: recycled marble bonds or forged receipts zero the attestation weight for that claim.","from":"poa1GpeX47fuLErtWF77q6FFRd2Dgkyg7ZnPJaR62htXJUud","nonce":7,"parents":["914f91dc52f95a75b07b4b1d34af9ee09ccfca9929da3ff809ca156b1a978d01","846acf272edf530a02e29fab7ca82e40d7478c4bc246e9ab603f4cee2152ccc2"],"ts":1793271213,"cid":"poa-mainnet-1","stamp":0,"sig":"42HC66NG8zPHie9LkJMfeWu6aN93YRbQXyShmhUVEiiTTeLMSERxS5v6wEAyWnEfBR25gDEh3acGME7zrnQT3tbL"},"checkpointed":{"height":144751,"note":"covered by a 5/5-signed, chain-anchored checkpoint — stronger finality than attestation count; atts freeze at coverage"},"as_of":"2026-10-31T00:47:56.957Z","checkpoint_height":144751,"source":"read-node-v0.2 (derived-only; open epoch refreshes every 45s)"}