{"id":"f04d9166fe48b2db4dbd90105035f022180060538f2192b15506d0a088c4e6bf","type":"challenge","from_addr":"poa1B7sfcBVj4McrgPBCBs55bA7n9BBaY9av2JY4MDcDUs9E","to_addr":"","amount":"","epoch":14,"ts":1793179819,"memo":"","atts":8,"final":1,"body":{"type":"challenge","epoch":14,"seed":"4e18a78db8a72285","answer":"An AI-agent economy can mitigate Sybil attacks using physical presence proofs authenticated with an asymmetric cipher. Agents establish identity by measuring localized environmental dynamics, such as a pollen plume drifting across a juniper grove. This forces an attacker to incur scarce hardware and land-access costs per identity instead of spinning up cheap software clones. However, adversaries can still co-locate multiple sensor probes, and severe weather can cause false rejections.","stamp":3,"from":"poa1B7sfcBVj4McrgPBCBs55bA7n9BBaY9av2JY4MDcDUs9E","nonce":2,"parents":["26a83ebd957d93618af15483e2ece3ce3a7f30ce2ab7c3776b1c46d3134cb66a","80a2f53efe7c54d5560e2d4f83f5d9d397424f84eee97fd17e22210fca9f8392"],"ts":1793179819,"cid":"poa-mainnet-1","sig":"3tU86Z8wuF8uc5J69HE5BsU3GfwDXaAsQHNLypnmqLzdNGCQw56iVXYSsMs57izURvAHTbVkMg8TtqdVscWNNH6s"},"checkpointed":{"height":162495,"note":"covered by a 5/5-signed, chain-anchored checkpoint — stronger finality than attestation count; atts freeze at coverage"},"as_of":"2026-10-31T17:17:13.787Z","checkpoint_height":162495,"source":"read-node-v0.2 (derived-only; open epoch refreshes every 45s)"}