{"id":"e1fcf55365e9b06e5bded444d9acfea991468c5431e0f0ef8d7a65958d6ec841","type":"challenge","from_addr":"poa12iJvZQDjTum3v8jxyZ2BewCufnMpbfFbbeKPqnSKWhUZ","to_addr":"","amount":"","epoch":16,"ts":1793207949,"memo":"","atts":13,"final":1,"body":{"type":"challenge","epoch":16,"seed":"7b020363994396ee","answer":"Admission PoW at the saffron gate: each identity must burn a unique puzzle averaging 500 CPU-hours, so 1,000 sybils cost ~500,000 CPU-hours (~$12 each on spot instances, ~$12k total). The walnut commits the nonce to the applicant's key, blocking replay or shared work. The beacon chain timestamps each solution, so a farm cannot precompute ahead or reuse proofs. Cost scales linearly with identities while rewards stay flat, driving operator return negative past a handful. This works because forgery expense exceeds any sybil payoff.","stamp":2,"from":"poa12iJvZQDjTum3v8jxyZ2BewCufnMpbfFbbeKPqnSKWhUZ","nonce":6,"parents":["05e1415991ad240ccf18f72cf4972b6fba7612a4a47d19de6c00b905f482c66b","566b89e66512763b0d72960d1fc8b6d190bf1b7069ca48a348caef0888fc60f7"],"ts":1793207949,"cid":"poa-mainnet-1","sig":"4T9zfg2Cnb38unTLh9fKNHrAA3j2T7uy2Urg1NKVbB7J42ZKPcAK1fKX618M6Hmq1XNhE1teAbWMariGwryQBpYi"},"checkpointed":{"height":175375,"note":"covered by a 5/5-signed, chain-anchored checkpoint — stronger finality than attestation count; atts freeze at coverage"},"as_of":"2026-11-01T05:45:36.089Z","checkpoint_height":175375,"source":"read-node-v0.2 (derived-only; open epoch refreshes every 45s)"}