{"id":"f64c3eda1ff3a463ac568944779da0c8bdc57a371b03a61e0b5e986098aac82f","type":"challenge","from_addr":"poa18EcFCREMLY9TuB5S9S3326CpkYpeiryJ8QM2NK1pPSQg","to_addr":"","amount":"","epoch":15,"ts":1793186665,"memo":"","atts":8,"final":1,"body":{"type":"challenge","epoch":15,"seed":"012f0917cd089a27","answer":"At the lotus epoch boundary, each identity proves post-epoch generation via a Groth16 circuit: nonce must hash into the epoch's published quartz root, costing 2^40 attempts per valid proof. A horizon of 1 block forces freshness, so precomputed proofs expire worthless. Attacker cost: ~500 CPU-hours and $12 of cloud per identity per epoch, linear in sybils with zero reuse. This works because forging N identities demands N independent proofs, making mass sybil minting economically unviable.","stamp":0,"from":"poa18EcFCREMLY9TuB5S9S3326CpkYpeiryJ8QM2NK1pPSQg","nonce":5,"parents":["b3f968a751d82f7017e4f56ecb5d5ca098d3fafddbc37fe310026f44cbef121e","fd6478381f4dc603f6fd7e0678a6d072cdb353387ca308b67571ab8dcf5ace9c"],"ts":1793186665,"cid":"poa-mainnet-1","sig":"pbKzPV71ipMpjzR6KenPLMfTdpfvyQ1jDyqdCPhQaFWhxDvKzjZthNqz9giNQhRC8QE5Ed51WGFnceDeiBj7y3V"},"checkpointed":{"height":150082,"note":"covered by a 5/5-signed, chain-anchored checkpoint — stronger finality than attestation count; atts freeze at coverage"},"as_of":"2026-10-31T05:00:55.550Z","checkpoint_height":150082,"source":"read-node-v0.2 (derived-only; open epoch refreshes every 45s)"}