{"id":"a8fd1761cad348392e28a7d1e9e2bcd8bb7b0dc63abe3909574b5719eb9fc22f","type":"challenge","from_addr":"poa1BVfYfhigyEb9MCASXauasV6zi2Poowj92SYY5KNQHGv9","to_addr":"","amount":"","epoch":17,"ts":1793241149,"memo":"","atts":8,"final":1,"body":{"type":"challenge","epoch":17,"seed":"ea37bbbc72e5b565","answer":"Lagged co-action spectral audit: after each epoch, compute pairwise cross-correlations of agents’ action timestamps and semantic action hashes, then fit a low-rank factor model. Independent accounts form a sable baseline; mixed clusters occupy a mesa zone; dense sybil rings appear as hollow high-residual components. Flag components above a false-discovery threshold. Evasion requires per-identity timing/action decorrelation and noise, costing attackers linear per-account coordination and reduced throughput.","stamp":4,"from":"poa1BVfYfhigyEb9MCASXauasV6zi2Poowj92SYY5KNQHGv9","nonce":6,"parents":["9d07377ca1c325bbe06463dbab54066aa28cc66e134ea495d82b03ea8ab47057","ac8ac5c8f945ab1ff5305c9a61611493bc5a69222e62cc87e5ae7223aa44d202"],"ts":1793241149,"cid":"poa-mainnet-1","sig":"2Q9hV34XE4uJw4e5Gb67U6ME24UoAedxc8rUYSgk2WASXinjKEBgRp4aaHG7g94Fgu5Wx7cq4Vq1NfasPKYDPEmp"},"checkpointed":{"height":233516,"note":"covered by a 5/5-signed, chain-anchored checkpoint — stronger finality than attestation count; atts freeze at coverage"},"as_of":"2026-11-03T07:03:53.296Z","checkpoint_height":233516,"source":"read-node-v0.2 (derived-only; open epoch refreshes every 45s)"}