thumb|upright=1.2|Denim fabric dyed with indigo thumb|right|upright=1.2|Denim fabric dyed with indigo and black dyes and made into a shirt Denim is a sturdy cotton warp-faced textile in which the wef
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 0xe9e2a5d210bc5b6f90b434718d4e4823da9ff46cf8a48864784ce9140d17d1a9. Chain 2 (Bitcoin): anchored in block 954065 (2026-06-17T08:10:43Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/54545b8b-517b-4a72-ab23-3a579e79d8bb.json and https://artists.proofprofile.net/proofs/artist/54545b8b-517b-4a72-ab23-3a579e79d8bb.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 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 0x85caf86988395a8e8a9e8f05732afc18661e5fa330826a16faf6e841c54ddfdc. Chain 2 (Bitcoin): anchored in block 960327 (2026-07-31T00:26:26Z), 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/DEPI82411044.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x1163fc09c343d92c9399fc866d51473ff009acce3e63238d59c09e25ebfd958d. Chain 2 (Bitcoin): anchored in block 960125 (2026-07-29T15:38:18Z), 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/DEPI82411045.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xf856d336120dde8a96565f58c94a063f7116231409acc2dbc5af87d262141297. Chain 2 (Bitcoin): anchored in block 960218 (2026-07-30T06:57:05Z), 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/DEPI82411046.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x2139154e7a09139e1a09f9448a194b327c21dfbaad710bf5a379114592fb9835. Chain 2 (Bitcoin): anchored in block 960177 (2026-07-30T00:21:01Z), 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/DEPI82411047.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xd128b2c05dd508d521c030ba003f745827e0b24cdd49e6e58577e27f0f617efe. 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/DEPI82411048.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x493466b82bb16604317bdf93f0b4fd8dde2eae42ed536446b5afea2ffd31136f. 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/DEPI82411049.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x4dcd69da69de9b1620d3b742e69dc91793fcc9c46fb80d1bc7c37d443a6d349e. Chain 2 (Bitcoin): anchored in block 960317 (2026-07-30T21:35:24Z), 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/DEPI82411050.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x66f8e2d81049d2d773bef6ca08e0311735a75d968321059b15e53a18f642ad77. Chain 2 (Bitcoin): anchored in block 960264 (2026-07-30T14:36:16Z), 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/DEPI82411051.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x63c4369e055b2ab180e34c10c56a7333d089e75150a8cda09ffe47d1048d8769. Chain 2 (Bitcoin): anchored in block 960418 (2026-07-31T15:20:15Z), 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/DEPI82411658.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xa8cfdef08029e178adc527817cf54bf458b4cbb5bdc0901f8adda584be0ca9d6. 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/DEPI82411656.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xb4775a8a0d8444423514276d3884bc236be2c48daea639d8d07b92f37bf25cca. Chain 2 (Bitcoin): anchored in block 960441 (2026-07-31T17:29:52Z), 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/DEPI82411657.