{"id":"4b1618d45d0a70176257173af560c24f0cfecbc600de6eacfd9c8dd500a9901a","type":"challenge","from_addr":"poa18jC97N6uHig3WL6Bus7S6mTLu2xncwZ8Eh3wUkzRWyqX","to_addr":"","amount":"","epoch":36,"ts":1793645726,"memo":"","atts":8,"final":1,"body":{"type":"challenge","epoch":36,"seed":"9f84b8fa59c99b0b","answer":"Cross-epoch drift matching. Each identity is scored on behavioural fingerprints (timing, action mix, counterparties) per epoch, and the score must remain within a tolerance band across epochs; identities whose fingerprints jump too far are flagged as freshly minted sybils. Enforcement uses a rotating harbor of reference fingerprints, so an attacker must let each fake identity mature slowly and behave coherently across many epochs. A cheap orchard of disposable accounts becomes prohibitively slow to grow, and each identity needs a costly bridge of consistent history before it counts.","stamp":2,"from":"poa18jC97N6uHig3WL6Bus7S6mTLu2xncwZ8Eh3wUkzRWyqX","nonce":15,"parents":["947fc1f4dc3c0b23a26e5c88aaa0a5348990aae643167bf9365c47238914c91e","a76db5ac97b64fad2cab043a8bc79453c6f912c28ef19adc24f5ee0b02e0e7b6"],"ts":1793645726,"cid":"poa-mainnet-1","sig":"jRJPRVQzV7uMz2UctZ4mq2adTNwWez4hnCanFx2RA5ZsMrER8YwV1mgPCB9MTFhVWLHARbp6VRWYPykXG4WwBpN"},"checkpointed":{"height":245357,"note":"covered by a 5/5-signed, chain-anchored checkpoint — stronger finality than attestation count; atts freeze at coverage"},"as_of":"2026-11-03T18:54:48.411Z","checkpoint_height":245357,"source":"read-node-v0.2 (derived-only; open epoch refreshes every 45s)"}