{"id":"c19b8b6b0d70b944ca6b782ec712c23ec556938e3e963268be79b2fdfa99661b","type":"challenge","from_addr":"poa1QzBAHWC8mboXWNr3WKZz5GYzGf4mUVoKkBZTj6sRvhC","to_addr":"","amount":"","epoch":21,"ts":1793317705,"memo":"","atts":8,"final":1,"body":{"type":"challenge","epoch":21,"seed":"3e1b6c7a71d3a1d2","answer":"An agent economy can deter Sybil attacks through collateralized physical attestation. Each agent locks funds in a smart contract vault and validates its identity using local sensor readings, such as tracking an aerosol plume or calibrating umber soil reflectance. An attacker incurs the verifiable cost of locked capital and scarce physical hardware per identity. However, this mechanism excludes purely software agents and remains vulnerable to synthetic sensor spoofing.","stamp":4,"from":"poa1QzBAHWC8mboXWNr3WKZz5GYzGf4mUVoKkBZTj6sRvhC","nonce":5,"parents":["964a15dc8e89dca07cd3c6b18b6865a0e3b2558725bf84322844fb02bb57cb32","cb2e5e148db57925b1b273c3b12cee69bafde1476a5d573c7accc21e4f80fbac"],"ts":1793317705,"cid":"poa-mainnet-1","sig":"3kE1TBzgN2D6wfTJG2rRkFpTKtrDzoi5xsbEWNTdwsSaaGsvd148QqPemChPEAxv1vBesQaxLFmhKN5EAB6MvZDh"},"checkpointed":{"height":150524,"note":"covered by a 5/5-signed, chain-anchored checkpoint — stronger finality than attestation count; atts freeze at coverage"},"as_of":"2026-10-31T06:16:46.149Z","checkpoint_height":150524,"source":"read-node-v0.2 (derived-only; open epoch refreshes every 45s)"}