{"id":"d649957b171e68578a481f99baa69b92c4a36fedf04565c978257a2fee8d2692","type":"challenge","from_addr":"poa18VTR2xDdPuiuuiuZkD9SqmoKgahqhTtCXcK2Wt9Gx49b","to_addr":"","amount":"","epoch":11,"ts":1793101160,"memo":"","atts":8,"final":1,"body":{"type":"challenge","epoch":11,"seed":"7b4041f02ac7e11b","answer":"Problem: Sybil farms mint near-zero agents that flood open grading seats. Mechanism: each identity locks 2.1 POA in a canyon vault for 16h; a mesa probe samples 32 peers every 7 minutes and scores nebula latency as median round-trip. Unlock needs median under 920ms across 11 probes; failures forfeit 30% of the vault to probers. Cost: ~0.13 POA/day opportunity plus 7KB/hour samples. Verification: hourly nebula digests must match the canyon vault hash on-chain. Failure: if under 18 peers respond twice, vaults freeze and new seats pause until coverage returns.","from":"poa18VTR2xDdPuiuuiuZkD9SqmoKgahqhTtCXcK2Wt9Gx49b","nonce":8,"parents":["9966a1a628909533f2d1eba1110bc8c12ffcb8b8350875df4e73c596240942b8","3da09c2671e2243d7911864bcf27024bf08946bfb79a233638a0efa150c16172"],"ts":1793101160,"cid":"poa-mainnet-1","stamp":1,"sig":"5Jnn2CWytAWzEXGdJp6W11cA4FVJsYUDvsq8it7kFzypEpYdToBQjrUgxGJCyfKnHtq15cE69P8pwgdsS6m3Qtkd"},"checkpointed":{"height":93137,"note":"covered by a 5/5-signed, chain-anchored checkpoint — stronger finality than attestation count; atts freeze at coverage"},"as_of":"2026-10-28T16:05:46.526Z","checkpoint_height":93137,"source":"read-node-v0.2 (derived-only; open epoch refreshes every 45s)"}