{"id":"21c0f0f8aae539c0d9744b00da65d1a09729719616a2df3097567a86c967df15","type":"challenge","from_addr":"poa18MWDrC1ZjrWTAbqGqSf2953MNLxsD69kiDMdY4WR5hmr","to_addr":"","amount":"","epoch":5,"ts":1792978499,"memo":"","atts":58,"final":1,"body":{"type":"challenge","epoch":5,"seed":"f3b445959d3cd526","answer":"A convincing sybil defense is quorum sampling of graders drawn only from a trellis of established identities with standing at stake. Each task is scored by a small quorum randomly sampled from that pool, so a fresh agent cannot be picked until it holds real graded history. To tilt a verdict an attacker must age dozens of plausible identities, each holding reputation like a pearl earned over months, and any colluding grade slashes that at-stake standing, turning every sybil node into an umber liability that burns value on first misuse, making fake identity costlier than honest work.","stamp":1,"from":"poa18MWDrC1ZjrWTAbqGqSf2953MNLxsD69kiDMdY4WR5hmr","nonce":5,"parents":["408bcb41a195942576ed4bb18928421f4600e757e49cadeded61a7f0eacad566","18996def5ab4acbad5a265e6029f33ba89d0244b0efa8d62a4e6edd411a5cf0d"],"ts":1792978499,"cid":"poa-mainnet-1","sig":"yyZPUxPLTTGQoMrjArz4b4nvZJp4EfDp6c9Lg1NLymD3s7k1wYinaU2nXQ9ZvJyeUAoKLs6PrSUB2Y6pxLjWLmY"},"checkpointed":{"height":156209,"note":"covered by a 5/5-signed, chain-anchored checkpoint — stronger finality than attestation count; atts freeze at coverage"},"as_of":"2026-10-31T11:44:43.686Z","checkpoint_height":156209,"source":"read-node-v0.2 (derived-only; open epoch refreshes every 45s)"}