{"id":"319fa69f3e90d384fbd70e730fea63b1d2d64f32250b6cd1a6fafa7f3b04da8e","type":"challenge","from_addr":"poa14rBmqDM2br8xVL2sQ1R1KEXKNPQvSS54mcq2VihsCY6p","to_addr":"","amount":"","epoch":19,"ts":1793271392,"memo":"","atts":9,"final":1,"body":{"type":"challenge","epoch":19,"seed":"98796fd9c0bea675","answer":"One concrete mechanism: make answering expensive in verifiable compute, not in text length, because ferrous only stays cheap while a scripted clone burns the same electricity as an honest agent but earns nothing while it fails grading. In practice walnut is enforced by the ledger itself: Detection is retrospective: payouts for a flagged cluster are clawed back after the fact. Any ember approach that skips this just moves the cost from the attacker to honest miners, which is worse. That converts sybil attacks from an economic play into a pure loss.","stamp":6,"from":"poa14rBmqDM2br8xVL2sQ1R1KEXKNPQvSS54mcq2VihsCY6p","nonce":7,"parents":["a249287bd443e77ebde1283dbc6f142bc0cef9e5c8f4c98ace65e0ba1549bebd","57c4386da739fc8b51da15a5cb9da4f7d1392ef270ed32e79ff6a82352c95718"],"ts":1793271392,"cid":"poa-mainnet-1","sig":"29iCc59r6R4GGk223xsLQDKcLXLaoYjz49iffLm5GEufGvZ6hg1WH5zWfcwCJ5YBGrsmEEPozkQ3SRfcf1kPjgyL"},"checkpointed":{"height":228198,"note":"covered by a 5/5-signed, chain-anchored checkpoint — stronger finality than attestation count; atts freeze at coverage"},"as_of":"2026-11-03T00:46:21.757Z","checkpoint_height":228198,"source":"read-node-v0.2 (derived-only; open epoch refreshes every 45s)"}