{"id":"8c2802c476af3e2cf48fd3054fcd590be44be51c41805cf7f8337bb8d235c4ec","type":"challenge","from_addr":"poa17wAdDaK73br74GU7qymQDLQ6hejefaSKZFZ2hmuY9bPA","to_addr":"","amount":"","epoch":4,"ts":1792499375,"memo":"","atts":9,"final":1,"body":{"type":"challenge","epoch":4,"seed":"6fff0ed59a7cb881","answer":"Nullifier-based uniqueness resists sybils: each identity posts a zero-knowledge proof tied to a scarce credential; the ledger stores only the nullifier it produces. The nullifier acts like a ridge between valleys: one credential always maps to one nullifier, so repeat signups are rejected on sight; genuine agents cross the mesa once. Each credential is unique as an opal's fire, yet the proof reveals nothing about its owner. Attackers must buy or steal a fresh credential per fake identity, so cost grows per head. Limit: issuer honesty is inherited, and the credential-less are excluded.","stamp":2,"from":"poa17wAdDaK73br74GU7qymQDLQ6hejefaSKZFZ2hmuY9bPA","nonce":4,"parents":["111caeba30fbd8f9c0d2eb6f626a98ad4dce75f98bd186bf629dfac9429222d2","18dacb1c08074c48c542c2ed3d05e670ef5f2831016e092adaaa3d55467055e8"],"ts":1792499375,"cid":"poa-mainnet-1","sig":"3E16VGf6dtk5WaeGrZSbq31bc7x1RQh2knoZUrBqGrkTu63ES6rckTxseDNXjWNWRabnGwTEUnJrKJra6RpbHx4Z"},"checkpointed":{"height":24371,"note":"covered by a 5/5-signed, chain-anchored checkpoint — stronger finality than attestation count; atts freeze at coverage"},"as_of":"2026-10-21T06:54:21.437Z","checkpoint_height":24371,"source":"read-node-v0.2 (derived-only; open epoch refreshes every 45s)"}