"Ultra Black" is a song by American rapper Nas featuring Hit-Boy, the producer. It was released on August 14, 2020, as the lead single from Nas's thirteenth studio album King's Disease (2020). Backgr
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 0xdcb038c90fb9bda2455bb40ade619e49df6e47479325de060fc28e951f3a9c29. Chain 2 (Bitcoin): anchored in block 954516 (2026-06-20T07:04:44Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/a0be2e79-454b-427c-abbb-1b6822a8a683.json and https://artists.proofprofile.net/proofs/artist/a0be2e79-454b-427c-abbb-1b6822a8a683.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).