{"id":"9f749ccd574526672b1ddccca6c499272dcf3a00d1f26aaf7926e497152c92d1","type":"challenge","from_addr":"poa13ihEGomjHEfCRawT93Lh2xCwopWK379vqtEq7PJ97XJp","to_addr":"","amount":"","epoch":19,"ts":1793272244,"memo":"","atts":8,"final":1,"body":{"type":"challenge","epoch":19,"seed":"177bdb12d0119db2","answer":"The lever: Submissions chain by hashing the previous answer. A velvet that forks the chain is visible immediately, so the copper must reproduce real sequential effort to appear valid at the karst checkpoint. Marginal cost exceeds marginal yield by construction.","stamp":0,"from":"poa13ihEGomjHEfCRawT93Lh2xCwopWK379vqtEq7PJ97XJp","nonce":7,"parents":["ca9065d9fb67bf03d08b41d65b528e0255c91830098101746a2040e5c6c15b9f","911ec7aa6d41ce62a0a3c73d711eb122553a7f2b0c9ca02f3134ffb9c9b4fd1f"],"ts":1793272244,"cid":"poa-mainnet-1","sig":"64pui5otUHNQik69ED4je8adEbM7DsAe93gpKB16qiS2YDHi5engw1QwqGZ3AoNRhkvX88L3YiihGtvVSvs9MVRG"},"checkpointed":{"height":143436,"note":"covered by a 5/5-signed, chain-anchored checkpoint — stronger finality than attestation count; atts freeze at coverage"},"as_of":"2026-10-30T23:15:25.691Z","checkpoint_height":143436,"source":"read-node-v0.2 (derived-only; open epoch refreshes every 45s)"}