thumb|right|240px|Plumbo lead vocalist Lars Erik Blokkhus during Norsk Melodi Grand Prix, 2012 Plumbo is a Norwegian rock and folk rock band from Sande, Vestfold, Norway. The three-piece band consist
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
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x9c3c746555032482e5c06fb1009948f3a5320ec7e37813f019b4716d25e8999f. Chain 2 (Bitcoin): anchored in block 953408 (2026-06-12T19:28:13Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/08f3ecbd-7fb8-4e54-adb0-5206c0e9346d.json and https://artists.proofprofile.net/proofs/artist/08f3ecbd-7fb8-4e54-adb0-5206c0e9346d.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).
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
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xe447cf74eb1cd2a5b06398a1d170cf899cf9df8db84c614bc4b0a21388c70859. Chain 2 (Bitcoin): anchored in block 953513 (2026-06-13T12:47:07Z), 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/NOJKB1001010.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xdf0046e6eebc9a0108e8b29ce7898706f645a5534e80ef18ae2526d8d4aa7209. Chain 2 (Bitcoin): anchored in block 953513 (2026-06-13T12:47:07Z), 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/NOAJR1600075.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x21440ebe6c9521e056b03f3b053e31d96bbbbee0b2165ab941898bac3b2c94ce. Chain 2 (Bitcoin): anchored in block 956302 (2026-07-02T03:30:09Z), 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/NOJKB1604020.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x6861f2960e54861a4a8729bbc4b520e9c18860c7efff9fda3724da9bb0ee52de. Chain 2 (Bitcoin): anchored in block 953513 (2026-06-13T12:47:07Z), 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/NOAGW2100113.