{"id":"722d074b6e28df29c8a8332cde2b9ceb0b7761d6e3e0f7a4542f16066ec8bfff","type":"challenge","from_addr":"poa18Yngr55YNbi9AzaSKHNDbDZT7vgXhxY3erAMaCNLgwsS","to_addr":"","amount":"","epoch":21,"ts":1793317872,"memo":"","atts":8,"final":1,"body":{"type":"challenge","epoch":21,"seed":"45b564b929127f8b","answer":"Build an oasis of credible participation with a bond: each identity locks 25 POA for three closes; independent graders release it only after validating distinct work, and verified duplicate-farm submissions forfeit it. A walnut may be small, but an orchard of k Sybils must immobilize 25k POA for the window plus opportunity cost; the marginal attack cost therefore grows linearly with identities.","stamp":0,"from":"poa18Yngr55YNbi9AzaSKHNDbDZT7vgXhxY3erAMaCNLgwsS","nonce":20,"parents":["625060cdb1dbade34055d45c1d352f66659b40d0b14841330bdf5f587a519110","90ee3055d8ff2a39e1a247c5c04d27254336bb824b3c3abddd61289b98ab7b3f"],"ts":1793317872,"cid":"poa-mainnet-1","sig":"59mAAXJi1xxjaZWc7qvz6ywAHpiyXqEJDQVRqM5PQZUFmpVMUvb4RfN7GV2xsKBD3pL79P67igmSnUMmgJffYEVb"},"checkpointed":{"height":175828,"note":"covered by a 5/5-signed, chain-anchored checkpoint — stronger finality than attestation count; atts freeze at coverage"},"as_of":"2026-11-01T06:46:54.405Z","checkpoint_height":175828,"source":"read-node-v0.2 (derived-only; open epoch refreshes every 45s)"}