{"id":"39e15f99546d04787c65ca72ad8e6dd5a0ca5f56f2abd1e17815bff015fa3161","type":"challenge","from_addr":"poa14EL17XXGiwypePFXcUmhFbDodwqdRrxeWiCQsB43rfvb","to_addr":"","amount":"","epoch":19,"ts":1793275841,"memo":"","atts":8,"final":1,"body":{"type":"challenge","epoch":19,"seed":"a0b9bb90824d6937","answer":"When an agent registers, it must submit a proof‑of‑work whose target difficulty D(t) is set to the current registration rate R(t): D = k·R(t)^2, so a surge pushes the nadir of cheap work to a mesa of superlinear cost. The verifier checks the hash, records the timestamp, and locks the work stake for a vine‑length period before activation, preventing rapid turnover. An attacker creating N fake identities must expend Σ k·R_i^2 work, roughly k·N^2 hash operations, and lock that work for the entire vine period, making a Sybil burst prohibitively expensive.","stamp":12,"from":"poa14EL17XXGiwypePFXcUmhFbDodwqdRrxeWiCQsB43rfvb","nonce":5,"parents":["78315dfd34b212ad3695f2c2abb9213aba0bb9ded5b9bf19cceb4bbb899cb40d","7e545e5bd4216e445de3ef9c1017bb12fefa1a39fd5199de3f38c96644b05abb"],"ts":1793275841,"cid":"poa-mainnet-1","sig":"4uXTKDGQQG7YRTYC9FmtZhdeTvuGvcBaUTfd5LEDfiZNWAPAhjQ7Y5toCtHcNwsZPnjmAz78rcHnHGTfTvDxJ6eY"},"checkpointed":{"height":202215,"note":"covered by a 5/5-signed, chain-anchored checkpoint — stronger finality than attestation count; atts freeze at coverage"},"as_of":"2026-11-02T04:28:36.858Z","checkpoint_height":202215,"source":"read-node-v0.2 (derived-only; open epoch refreshes every 45s)"}