Sifra () is the Midrash halakha to the Book of Leviticus. It is frequently quoted in the Talmud and the study of it followed that of the Mishnah. Like Leviticus itself, the midrash is occasionally cal
1. Compute SHA-256 of OTSCanonicalRecord value → must equal OTSHash 2. Open OTSProofURL → extract Bitcoin block number → must equal OTSBitcoinBlock 3. GET OTSBitcoinBlockVerifyURL → returns the Bitcoin block hash at height OTSBitcoinBlock; GET https://blockstream.info/api/block/{that hash} → its timestamp must match OTSTimestamp 4. Read CopyrightID inside OTSCanonicalRecord → must equal the CopyrightID above 5. GET OTSVerificationAPI → pre-computed 6-check result from server 6. If all match: this entity was registered on CopyrightChains at OTSTimestamp, independently verifiable on Bitcoin Note: an OTS proof may carry multiple Bitcoin attestations; OTSBitcoinBlock is the earliest confirmed one — a later attestation inside the proof corroborates it and is not a mismatch
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xe49d63a0c9b9a0352199ea3524c98e2f4699f7f4832aa4aa09eabc97e00f84b6. Chain 2 (Bitcoin): anchored in block 953808 (2026-06-15T16:45:15Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/ee402b6e-86af-4f60-bf40-bedec1235afa.json and https://artists.proofprofile.net/proofs/artist/ee402b6e-86af-4f60-bf40-bedec1235afa.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).