"Heartline" is a song by British singer Craig David. It was written by David, Jonas Blue, and Sam Romans and produced by Blue for his seventh studio album, The Time Is Now (2018). The song was release
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 0x492a6163bfb56936eba49cca6f4dce95c5cc81dc8d5a3bc449fd9a4ba6b1a047. Chain 2 (Bitcoin): anchored in block 954618 (2026-06-20T23:05:13Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/c9660310-902c-48cd-ae24-6637251f91ad.json and https://artists.proofprofile.net/proofs/artist/c9660310-902c-48cd-ae24-6637251f91ad.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).