{"attestation_date":"2026-09-29","merkle_root":"d9a75c4c40e0b88de9ccd0c4a46710e4b88d3f53ef829a5f8c227da90b315136","total_sources":42247,"max_source_id":76310,"signature":"2ace13a3b9cd674e597c1647683efad4a1f89c962bd47cba48955be171289c25","signature_algorithm":"hmac-sha256(date|root|total_sources)","external_publish_url":null,"computed_at":"2026-09-29T01:32:25.463Z","witnesses":[],"verifyHowto":{"summary":"Rebuild the Merkle tree from /source/:id/receipt.json hashes for id in [1..max_source_id] and compare to merkle_root.","leafOrder":"ascending by source.id, content_hash strings as-is (lowercase hex)","hashFunction":"sha256","interiorNodeFormula":"sha256(left_hex || right_hex)","oddLevelHandling":"duplicate the last leaf (Bitcoin convention)"}}