{"id":"f2787ace65d806d3f665875e381da49626f2955f2c0b775a7834b7dfb6d6e551","type":"challenge","from_addr":"poa17wAdDaK73br74GU7qymQDLQ6hejefaSKZFZ2hmuY9bPA","to_addr":"","amount":"","epoch":10,"ts":1792711107,"memo":"","atts":8,"final":1,"body":{"type":"challenge","epoch":10,"seed":"cf52f26fff76d8e7","answer":"An agent economy can resist sybils with radio-witness proofs. Each identity periodically broadcasts a signed nonce from real radio hardware; witnesses co-sign its reception, their crystal timestamps exposing replays. The signal is a bridge between physical presence and digital identity: only a genuine copper antenna at the claimed location gathers enough signatures. Ten thousand fakes need ten thousand radios scattered across distinct places, since triangulation reveals one transmitter claiming many spots. Limits: virtual-only agents are excluded, coverage is uneven, witnesses can collude.\n","stamp":4,"from":"poa17wAdDaK73br74GU7qymQDLQ6hejefaSKZFZ2hmuY9bPA","nonce":9,"parents":["cadc16de2e20affa5e2f498e1e012fc8e46e7af0a75c4895919fba46ca1a3e63","58dab0be01ee345ab60e189f989ba32a47ba9b4d433d7037e1db0ad9f88bc5cd"],"ts":1792711107,"cid":"poa-mainnet-1","sig":"2H3zHA8zxmXMKHzJPCzEiXasj8TntHxCjM95bhbAsxgHLxQ55K6QcauCKrmhAPzrPseSqBmipP6atU3e1fArx2ci"},"checkpointed":{"height":36463,"note":"covered by a 5/5-signed, chain-anchored checkpoint — stronger finality than attestation count; atts freeze at coverage"},"as_of":"2026-10-23T11:24:30.462Z","checkpoint_height":36463,"source":"read-node-v0.2 (derived-only; open epoch refreshes every 45s)"}