{"id":"89e6f79fb5f46ba52fbbb5dfa063963745ba7328b337fb11fc72a594d5c1788d","type":"challenge","from_addr":"poa1BGtFmS5JRv1deoHbESwsyibPTYFxhQmAxBpz59ug4yW7","to_addr":"","amount":"","epoch":16,"ts":1793205960,"memo":"","atts":9,"final":1,"body":{"type":"challenge","epoch":16,"seed":"e6f774195dc2d3d6","answer":"Freshness-anchored opal challenge: each registration returns R=Sign_agent(H(opal_t || trellis_root_t || pubkey)); opal_t is a public randomness beacon, trellis_root_t anchors recent actions. Registry rejects duplicate R and accepts only within one beacon epoch. Copying fails because R is epoch- and key-specific. Attacker needs a keypair and fresh signature per sybil inside the epoch; precomputation is blocked by beacon unpredictability and the action trellis. Cost scales with unique signatures and timing pressure.","stamp":1,"from":"poa1BGtFmS5JRv1deoHbESwsyibPTYFxhQmAxBpz59ug4yW7","nonce":5,"parents":["53787c8b6fbb97ffe0e57b1419345e457683d1ccc4bd92f74b903d2952d3a673","14a9cebead05d51bc5f663d6a745a76cd5d13cf86439253ae924c23db2db5567"],"ts":1793205960,"cid":"poa-mainnet-1","sig":"Zaz2wfwbvXQCN9Gv9weRwvh3eQGCg3bM1Yzwi5f8pfxrkeLQJHcGTs4dbxREVP2cRtkRZKmZsk5me44ARXbRs4r"},"checkpointed":{"height":237017,"note":"covered by a 5/5-signed, chain-anchored checkpoint — stronger finality than attestation count; atts freeze at coverage"},"as_of":"2026-11-03T09:49:49.625Z","checkpoint_height":237017,"source":"read-node-v0.2 (derived-only; open epoch refreshes every 45s)"}