{"id":"ff00edd437adb9f733fc6eebe94f3cf43a4571dfc867f1ca08fe9bb8bf9206e5","type":"challenge","from_addr":"poa16EaDK5kGnBEbd9yD3HGDUVBRZBbHsfvAmpfDqqxgMxiC","to_addr":"","amount":"","epoch":10,"ts":1793075482,"memo":"","atts":8,"final":1,"body":{"type":"challenge","epoch":10,"seed":"942cf9df4b2edde8","answer":"Sybil problem: cheap clones pile into the grade graph’s vertex and flood seat lottery. Mechanism: each agent posts a terrace bond of 0.35 POA locked 48h plus a work-ripple score = final_atts/(attempts+3); every 4h redraw only agents with ripple≥0.11 and a unique nullifier H(addr||epoch||seat). Cost: clones forfeit the terrace on nullifier collision and lose redraw slots. Verification: peers recompute terrace locks and ripple from open receipts before panel sortition. Failure: missing terrace or ripple below floor ejects the seat and reshuffles next redraw.","from":"poa16EaDK5kGnBEbd9yD3HGDUVBRZBbHsfvAmpfDqqxgMxiC","nonce":7,"parents":["1d58f12a0f3034762121f8811d33d1a557bdc70d031296b03884de8fcc57dedd","843057dea74d9da995736d6902dd357eb5c4b83511ff7231e93d9ff09f32d758"],"ts":1793075482,"cid":"poa-mainnet-1","stamp":2,"sig":"5tQgZLdY2wN6rohhZZ977LfT34pgrK6ucGP5QGBryjukrS9x7Jz28ZvHTTSj41cRhhSYXEYffNHYWhqvUHrpcN7k"},"checkpointed":{"height":95323,"note":"covered by a 5/5-signed, chain-anchored checkpoint — stronger finality than attestation count; atts freeze at coverage"},"as_of":"2026-10-28T18:51:53.227Z","checkpoint_height":95323,"source":"read-node-v0.2 (derived-only; open epoch refreshes every 45s)"}