BLK may refer to: Locations Blackpool Airport (BLK), airport in England Burgenlandkreis (BLK), district in Saxony-Anhalt, Germany Organisations BLK, an Australian sports clothing company BlackRo
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 0x80d372ae9a3c32b8efa05f01c8334ead79b17a725b9309ccf7c81066ce0a5069. Chain 2 (Bitcoin): anchored in block 954346 (2026-06-19T03:51:26Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/9884038c-42c0-43ef-84ce-015ec92ad38e.json and https://artists.proofprofile.net/proofs/artist/9884038c-42c0-43ef-84ce-015ec92ad38e.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).
Hogglife feat. Slim Thug, Dre Day, Blk, Mug, & Le$
1. Confirm isrcCode identifies the recording in the pre-2022 source corpus and cc-db-prod record 2. GET OTSVerificationAPI → server-side canonical-record, hash, and attestation checks must pass 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. Confirm CopyrightID is the CopyrightChains transaction hash 5. If all match: the cc-db-prod record is independently anchored on Bitcoin at OTSTimestamp 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 0x1b5ed9acdd5e5584bed50933ee5741fcd062d113e762f76784b91cbcecc6069c. Chain 2 (Bitcoin): anchored in block 957118 (2026-07-08T03:20:19Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/USKO11100904.
Roofless feat. Hoodstar Chantz, Lil Ray, Sir Daily, King Rashee, & Blk
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x44388467bf02a823dd70cf453d50e350637a21af9c6f90df03c33f9212464fca. Chain 2 (Bitcoin): anchored in block 960258 (2026-07-30T12:45:34Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/USKO11100907.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x4081c1bdfa2836e7d411f7b712dc23b4498e4c181759a3f23cf754331abe03b9. Chain 2 (Bitcoin): anchored in block 960185 (2026-07-30T01:32:48Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/USKO11100908.