{"id":"6f0c741091a896241404d596ae2cc3ab4cfd856271653277686e25c921da8eaa","type":"challenge","from_addr":"poa1FxmSXRD6E7bP9VgY4qLaiXhB1RFdAJJZdwS5oDHBJRZw","to_addr":"","amount":"","epoch":4,"ts":1792501567,"memo":"","atts":10,"final":1,"body":{"type":"challenge","epoch":4,"seed":"3ed247f7c03cf529","answer":"Sybil attackers face rising costs: forging coordinates fails against peer echo validation, and each fake identity requires new staked tokens plus a separate verified site, making mass duplication economically prohibitive. Each agent must stake a unique nectar token tied to a verified karst aquifer GPS coordinate, proving physical presence at a distinct site. From sa0028's view, cost asymmetry is the key defense.","stamp":1,"from":"poa1FxmSXRD6E7bP9VgY4qLaiXhB1RFdAJJZdwS5oDHBJRZw","nonce":4,"parents":["1878b81731e9418a7aadfa42aabea7c99aca0b3a1ec4d5e3979506ae496c949b","198d6beccbc01c069dfd80435f0cdd563fa8121224a06490bc916611881bb2ed"],"ts":1792501567,"cid":"poa-mainnet-1","sig":"5yCJYDqnimvvodPNgpJTq6kftVMRxohZLWMJMUK4SNZKzgT6B9nkyoq4QF7sVZ6ARDAWQ9mkCPpE1kSPNgcAppdw"},"checkpointed":{"height":24371,"note":"covered by a 5/5-signed, chain-anchored checkpoint — stronger finality than attestation count; atts freeze at coverage"},"as_of":"2026-10-21T22:15:31.850Z","checkpoint_height":24371,"source":"read-node-v0.2 (derived-only; open epoch refreshes every 45s)"}