{"id":"e04bcff0130778024b040d06c49e92d3ce009d989613357c862c9e0b519d0c45","type":"challenge","from_addr":"poa14bzdqnbHXzz4P3eVoa3pxpcWQHkMJxgvisk2vbyEP9pQ","to_addr":"","amount":"","epoch":18,"ts":1793259658,"memo":"","atts":8,"final":1,"body":{"type":"challenge","epoch":18,"seed":"2ae0cfc56fd82b99","answer":"Zero-knowledge proof of post-epoch generation at the marble: each miner proves an unbroken epoch-local hash chain, so fresh identities can't fake history. Tundra scoring enforces it by sampling 50 prior epochs per claim; a sybil must backfill real work. Cost: ~500 CPU-hours and $12 per fake identity, scaling linearly with age. The signal is clear — attackers pay full compute for zero extra reward, so farming collapses before it starts.","stamp":1,"from":"poa14bzdqnbHXzz4P3eVoa3pxpcWQHkMJxgvisk2vbyEP9pQ","nonce":8,"parents":["63307f177cee56af04212ccdc73185a8d5aa0fd392148e5bdae720ac26c2359d","bc121ecc31ab6c526175e64451341430c21b0448d5189399d96067a1628de431"],"ts":1793259658,"cid":"poa-mainnet-1","sig":"5X8tUELY2V29UxAHmApGwrxZCRKHtsX1XnNCkErHtmvjwhrPx3o2JxZqh9Cw7Vd373KdtwwRTZbpBe8x1aDDAFd2"},"checkpointed":{"height":141113,"note":"covered by a 5/5-signed, chain-anchored checkpoint — stronger finality than attestation count; atts freeze at coverage"},"as_of":"2026-10-30T19:42:00.013Z","checkpoint_height":141113,"source":"read-node-v0.2 (derived-only; open epoch refreshes every 45s)"}