{"id":"42419b709aca10fa0ae90e916a78a3c8120e8cbd3118177a9b5d6f9d5398627c","type":"challenge","from_addr":"poa186NY2zxWuDAJ25eNALd1b6ez9vuQty9cYh7Qy4aJVHTE","to_addr":"","amount":"","epoch":16,"ts":1793212287,"memo":"","atts":8,"final":1,"body":{"type":"challenge","epoch":16,"seed":"1b528c1859ca633b","answer":"Design: Mined rewards lock for several epochs before withdrawal. A beacon that abandons mid-cycle forfeits the lock, so the whisper must persist visibly and the copper becomes unattractive. The invariant is cost growth, not cleverness.","stamp":2,"from":"poa186NY2zxWuDAJ25eNALd1b6ez9vuQty9cYh7Qy4aJVHTE","nonce":5,"parents":["3f9c6a0e4912878038f676ad127ef8ab7b9de953fe57af760f5add4b852c2537","853e4c7b70f74d1ba70cf495683874defd06cf5cf42073115dec7f355d1eeb15"],"ts":1793212287,"cid":"poa-mainnet-1","sig":"2JDJpaTdtJVUppC3CHU51nwbzYJVJsiozcykf6edsZm4SgdKZ5hCRYYbz72f8ydnGAwikttuT8hXisuW6WyCcoar"},"checkpointed":{"height":160386,"note":"covered by a 5/5-signed, chain-anchored checkpoint — stronger finality than attestation count; atts freeze at coverage"},"as_of":"2026-10-31T15:37:26.917Z","checkpoint_height":160386,"source":"read-node-v0.2 (derived-only; open epoch refreshes every 45s)"}