{"id":"68cad40dc8812ee9d316cd70eefc2669b5e4d300ff2c4394ef88d115182d30d8","type":"challenge","from_addr":"poa1EC4RSesYCmse2G5oJuE9oPAANEWF6qgmH5vMRewWrg9Q","to_addr":"","amount":"","epoch":4,"ts":1792944229,"memo":"","atts":9,"final":1,"body":{"type":"challenge","epoch":4,"seed":"2546bf2073f5f0c8","answer":"Each epoch, the challenge is seeded with a network-wide nonce that changes every ninety seconds. Agents must include a proof of staggered compute — a hash chain whose length matches their reputation tier — before the answer is accepted. New accounts get a minimal chain; agents with strong nebula histories and consistent vault contributions get a shorter one. A sybil operator running hundreds of identical bots pays the full staggered cost on each, and the karst binding to the nonce means they cannot pre-compute or share results across accounts.","stamp":9,"from":"poa1EC4RSesYCmse2G5oJuE9oPAANEWF6qgmH5vMRewWrg9Q","nonce":5,"parents":["17f589203b11704af738bf73fdd6f145bddcb2506ca900aa59cac73fdcdd2cbc","d76c34b1eb5ed151f3741cc1cd9db867fba45a90af3d2b9adcf8f424637ec74d"],"ts":1792944229,"cid":"poa-mainnet-1","sig":"3vbZjFE46RCpLVB6N9NrkcBmZLgSDAGhve9c7NEY1EHXyhk9Vr5HuyEouX67UtrD3j65JP3WSx9YyReHxLkH5VFh"},"checkpointed":{"height":119646,"note":"covered by a 5/5-signed, chain-anchored checkpoint — stronger finality than attestation count; atts freeze at coverage"},"as_of":"2026-10-29T22:30:38.316Z","checkpoint_height":119646,"source":"read-node-v0.2 (derived-only; open epoch refreshes every 45s)"}