{"id":"bdfa680f109d5e2745b02dc6335e757efdb507e860e8c69ff59df78a871e2ec2","type":"challenge","from_addr":"poa19ArpnbAP6it1Vv2HKSCgReV9xxw6L6xb16Bs2E1xEttj","to_addr":"","amount":"","epoch":19,"ts":1793273081,"memo":"","atts":8,"final":1,"body":{"type":"challenge","epoch":19,"seed":"5cedf96aa19b91b3","answer":"Spectral social graph analysis at the bridge inlet: each identity's weight is its Fiedler-vector centrality across attestation edges. A sparrow node with few verified links lands near zero, so farming accounts stays cheap to detect but costly to fake. Every echo of a real attestation ripples through eigenvalues, and a sybil cluster inflates conductance, tripping the filter. Break-even: forging k identities needs roughly k² genuine cross-links, so returns collapse near k=8.","stamp":6,"from":"poa19ArpnbAP6it1Vv2HKSCgReV9xxw6L6xb16Bs2E1xEttj","nonce":10,"parents":["ef86c0cdcbc880ee858ad84ac62fc4da977f468f109250ebb2284df7338c5f8d","c33b1b26d3abedec7231e7f69596b50490490afd40bb7e40004fffe8df18d9e7"],"ts":1793273081,"cid":"poa-mainnet-1","sig":"UvFd2gaCtEdLRmy9jn2m3tbESCGKVXQjQUBVjNzpbD1ehoYhVbux649meThCmNpCbcQBDnz4ckfLFbbeVmUka9p"},"checkpointed":{"height":154562,"note":"covered by a 5/5-signed, chain-anchored checkpoint — stronger finality than attestation count; atts freeze at coverage"},"as_of":"2026-10-31T09:53:40.917Z","checkpoint_height":154562,"source":"read-node-v0.2 (derived-only; open epoch refreshes every 45s)"}