200px|thumb|The recording at Det Kongelige Bibliotek released on Dacapo Records in 2006 Højskolesangbogen of the Danish adult Folk high schools is a songbook established by Heinrich von Nutzhorn in 18
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 0x84134cbe93a5368e5669e21e54cfa4aab8a762aefccf74e533ced0e104a6d6f3. Chain 2 (Bitcoin): anchored in block 953407 (2026-06-12T19:24:56Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/6b5f304b-80f9-4792-b0c7-30f255120c1d.json and https://artists.proofprofile.net/proofs/artist/6b5f304b-80f9-4792-b0c7-30f255120c1d.ots, the client at https://opentimestamps.org runs `ots verify -f record.json proof.ots`.
Det Blå Sanghæfte - Klaverakkompagnement til fællessang
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 0xc5bd13c51324b4068fe7324078b14df339d3bfd5981121cc16e5725f8b4dd67b. Chain 2 (Bitcoin): anchored in block 958627 (2026-07-18T23:33:54Z), 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/DKMP21600108 — a six-check JSON result.
Halfdan - Klaverakkompagnement til fællessang
100 Sange fra Højskolesangbogen – Klaverakkompagnement til Fællessang
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xbd3c23454916e1c86888e42ebd564a7cd91447cf2c6fcb29de88f37c5de78680. Chain 2 (Bitcoin): anchored in block 956822 (2026-07-05T18:48:28Z), 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/DKMP21800101 — a six-check JSON result.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xa4d5fec33643656336883148e63eca41d3ebf91bbb5fda48ed25de0d4dcefbea. Chain 2 (Bitcoin): anchored in block 956725 (2026-07-05T01:12:41Z), 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/DKMP21800103 — a six-check JSON result.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xc65f280d5f37664750b90ed32ca4d3693415dc02e1121961e227a3bcc5acdca4. Chain 2 (Bitcoin): anchored in block 958647 (2026-07-19T02:36:14Z), 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/DKMP21800104 — a six-check JSON result.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x9702d3ae68767d6e71f32bddc2424e8794efa3ed5e223992de764b83e8a6e4a8. Chain 2 (Bitcoin): anchored in block 958857 (2026-07-20T09:45:25Z), 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/DKMP21800105 — a six-check JSON result.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x06eb4f39a5e04270b49a2a63a1eb96b29fe8ead373edf2e30b7abca8c05927da. Chain 2 (Bitcoin): anchored in block 958653 (2026-07-19T03:54:23Z), 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/DKMP21800107 — a six-check JSON result.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x6651f180166ab4437a93a5d493dea05605700097df3f4e3b19cf304b2d3b9448. Chain 2 (Bitcoin): anchored in block 958137 (2026-07-15T09:47:57Z), 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/DKMP21800116 — a six-check JSON result.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x222f1cbd05b9e3da97c3706c522ac8dfe9a4c4ea390a407e289ec0108f686394. Chain 2 (Bitcoin): anchored in block 957884 (2026-07-13T16:55:06Z), 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/DKMP21800128 — a six-check JSON result.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x2459821bc0ff47aaa2e743678a9635dfa182de3f14b555738855dfc54a8bac97. Chain 2 (Bitcoin): anchored in block 958224 (2026-07-16T02:28:43Z), 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/DKMP21800129 — a six-check JSON result.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x1691c24d7b5d18afc4edc7eca932cbbc9665366838b045698ed1bb74b1e2f992. Chain 2 (Bitcoin): anchored in block 956725 (2026-07-05T01:12:41Z), 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/DKMP21800139 — a six-check JSON result.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x99645ef97280bc5436eab5d8a68256197c791b49474b1cb18fff0343ac7163be. Chain 2 (Bitcoin): anchored in block 958633 (2026-07-19T00:54:50Z), 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/DKMP21800143 — a six-check JSON result.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xcd2b9092d83d1c72d03ac0edd4b0d20b07f11886329bafc798e8c25d0e1d03d3. Chain 2 (Bitcoin): anchored in block 956826 (2026-07-05T19:27:56Z), 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/DKMP21800155 — a six-check JSON result.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x1fc922fd4c7c7f6c6b7f8c9d56f7d40677cb6352f41b1111e3c9062b1fa818a1. Chain 2 (Bitcoin): anchored in block 958461 (2026-07-17T23:18:11Z), 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/DKMP21800173 — a six-check JSON result.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x75c42c735629371e8a1062bebcb4aae2569654f773f345ebd1fe5ac2e775c3bd. Chain 2 (Bitcoin): anchored in block 959008 (2026-07-21T13:14:05Z), 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/DKMP21800189 — a six-check JSON result.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xacdeb5953a470f3774914826a4245692f1c665f5e043ba83b5a117bcf9f42568. Chain 2 (Bitcoin): anchored in block 958371 (2026-07-17T05:45:43Z), 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/DKMP21800190 — a six-check JSON result.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x7b445292644078daddd219b8d1dc4c112441131e8ae1838ec3f7b1b5208f5ed6. Chain 2 (Bitcoin): anchored in block 958839 (2026-07-20T07:01:59Z), 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/DKMP21800198 — a six-check JSON result.
Højskolesangbogen for Børn - Klaverakkompagnement til Fællessang
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x0a8740fd10c879de8f91b2f98117eda130c76052d8da7346c338ad7ef99e9cc3. Chain 2 (Bitcoin): anchored in block 956822 (2026-07-05T18:48:28Z), 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/DKMP22000304 — a six-check JSON result.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x1b8debf46868485b4eafc1ad93fac82435afdc303e422af26aac2caa3cb81ef0. Chain 2 (Bitcoin): anchored in block 958911 (2026-07-20T16:46:31Z), 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/DKMP22000368 — a six-check JSON result.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xe4e24de3d2c32f0415307430b4d57a9da29111f72cf2ce3ff0c9e3fb8f714e0d. Chain 2 (Bitcoin): anchored in block 956545 (2026-07-03T19:59:51Z), 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/DKMP22000383 — a six-check JSON result.
Højskolesangbogen for børn - klaverakkompagnement til fællessang