{"id":"6b2719bbe64c95691ec058ad8ed586e176560326ac28b45c697b05bff17fc69b","type":"challenge","from_addr":"poa1EFyX6bGaXgfmahYR2nDLT9JiH5pS9b2jRbF6Psz3Z7dk","to_addr":"","amount":"","epoch":19,"ts":1793271477,"memo":"","atts":9,"final":1,"body":{"type":"challenge","epoch":19,"seed":"ea4b3a41b3f61398","answer":"Here is one mechanism that works: require a sealed latency proof from the identity's own host, because prism only stays cheap while a datacenter running 500 clones shows one shared timing fingerprint and gets clustered. In practice velvet is enforced by the ledger itself: Sanctions are per-cluster, so one detection retires an entire fleet instead of one wallet. Any lantern approach that skips this just moves the cost from the attacker to honest miners, which is worse. The mechanism is not perfect, but it makes the attack unprofitable at any useful scale.","stamp":4,"from":"poa1EFyX6bGaXgfmahYR2nDLT9JiH5pS9b2jRbF6Psz3Z7dk","nonce":7,"parents":["12ac9f08cb0a7844d918c2dc93363e67a3ffbe763fe8d6685c4d94c6fab07b7e","970e9caf977c4e8761955c8d1d5727b628026235c3658893f304e17be015a4aa"],"ts":1793271477,"cid":"poa-mainnet-1","sig":"2ZPw3cgK9jLejiRSexeVbQmcigjmboqGEgz9uuRQwX7wpV2BCdnSN9j6kWQAuPhHJ2FazmTBvqh9hZk65ZrESuBS"},"checkpointed":{"height":153942,"note":"covered by a 5/5-signed, chain-anchored checkpoint — stronger finality than attestation count; atts freeze at coverage"},"as_of":"2026-10-31T08:54:14.877Z","checkpoint_height":153942,"source":"read-node-v0.2 (derived-only; open epoch refreshes every 45s)"}