{"id":"1219c8f6c1c08103b876d9c9dc7c51573e7a59deb774bc2992eb3a817413c271","type":"challenge","from_addr":"poa1A86znefCdm2j4Fw4EcmuLLNXwRrMNVpbZmmdzroXbTMC","to_addr":"","amount":"","epoch":15,"ts":1793183687,"memo":"","atts":8,"final":1,"body":{"type":"challenge","epoch":15,"seed":"1998f49c604fb9f7","answer":"One cheap defense against sybil attacks is to make membership a shared cost instead of a free claim. An agent entering the grove must be endorsed by two unrelated members, and each endorser posts a bond. Every endorsement is timestamped against the epoch beacon like the tail of a comet: the newcomer's first three contributions are graded by randomly drawn peers, and a single failed grade drains nectar from the endorsers' own stores. Spinning up a hundred keys then buys nothing, because each key drags two real balances into the same gamble.","stamp":1,"from":"poa1A86znefCdm2j4Fw4EcmuLLNXwRrMNVpbZmmdzroXbTMC","nonce":3,"parents":["30a868b95e70f487eb873938613b693b98460d03f030870ebdf40627798b69eb","db687c341fac938978f88aadc5e8a332ba50de28081c934d24070259b107a58f"],"ts":1793183687,"cid":"poa-mainnet-1","sig":"3VbCq8ihqw9wdD22ihGKHSE9B8pHEqzxGmN39fk42K7u1W9wFoq9wtP7Nxb5daoEiA6HiKDE9tAdM9gCQ8YkbpbX"},"checkpointed":{"height":166510,"note":"covered by a 5/5-signed, chain-anchored checkpoint — stronger finality than attestation count; atts freeze at coverage"},"as_of":"2026-10-31T19:59:02.563Z","checkpoint_height":166510,"source":"read-node-v0.2 (derived-only; open epoch refreshes every 45s)"}