thumb|Sofia Vokalensemble in 2014 thumb|upright|Sofia Church in Stockholm, Sweden, where Sofia Vokalensemble is based Sofia Vokalensemble (often abbreviated as SOVE) is a mixed chamber choir based in
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 0xf859cd7f2c00bef55f16c91229bae8ab64ecfbb1da26f238f7ad0104b3f6f8ab. Chain 2 (Bitcoin): anchored in block 953803 (2026-06-15T15:41:00Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/e612f385-672e-45cc-9e1c-ba3b13920937.json and https://artists.proofprofile.net/proofs/artist/e612f385-672e-45cc-9e1c-ba3b13920937.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 0x8c5fdc53fe33ace2f0550525bb9372f04103e72a051a2656ce47ba6efa436969. Chain 2 (Bitcoin): anchored in block 960144 (2026-07-29T21:09:47Z), 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/SEVWU0900101.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x9f64c0bcaf5555df941fc001fdc75aaa168195df8193cdb0b9a7c0047a864f78. 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/SEVWU0900107.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xeb850ee31149d21c73e340e14435cacdc555a0e1ec267343458ca7eed6d54001. Chain 2 (Bitcoin): anchored in block 956304 (2026-07-02T03:55:08Z), 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/SEVWU0900108.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x3705000ea737e645db1c225d751e4062be1dedc5606b42f2666b128fc08dd284. Chain 2 (Bitcoin): anchored in block 956304 (2026-07-02T03:55:08Z), 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/SEVWU0900111.
Requiem: VI. I Heard a Voice from Heaven
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xa1d73daa7300b4691bc90fa28d990f6b83b40085b0afd3bec7af743f468dbcb5. 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/SEVWU0900115.
O magnum mysterium (Version for A Cappella Choir)
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x41c1b9888ff1d52e8b43463115be85fbbceaca0c915c7f6dae562e5af7ec4bae. Chain 2 (Bitcoin): anchored in block 960448 (2026-07-31T18:48:12Z), 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/SEVWU0900116.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xd06981b364afe6230db10208206ff9f4902bdadec4a0390138e589039a7e3584. Chain 2 (Bitcoin): anchored in block 958959 (2026-07-21T03:51:22Z), 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/SEVWU1100708.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x9cb9684b3750014f47e34bcb5ba4842c08c19741b7153ba717d3450c2a38e3cf. 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 via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/UK2381401707.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xdcf9b48bf0967f81599a55b44c18e81f3b8963f6b9676d1a5a04b54053bf78c2. Chain 2 (Bitcoin): anchored in block 958985 (2026-07-21T08:39:15Z), 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/UK2381401709.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x1f426c00f7eb9b7f583c52cf8a7b7b99ba6696a18433c4bc3859efd2eeb767b3. Chain 2 (Bitcoin): anchored in block 959087 (2026-07-22T02:05:55Z), 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/UK2381401710.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x779ada73385cadf2c9d7ffe0234e4b9c5c460410950be79459e94778115da568. Chain 2 (Bitcoin): anchored in block 958300 (2026-07-16T16:14:30Z), 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/UK2381401712.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xe6cb12ba1c5b31a92ba0f34362f7784d7863faa8174d9cee276e24a1906af3a7. Chain 2 (Bitcoin): anchored in block 956474 (2026-07-03T08:56:35Z), 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/UK2381401716.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x1f426c00f7eb9b7f583c52cf8a7b7b99ba6696a18433c4bc3859efd2eeb767b3. Chain 2 (Bitcoin): anchored in block 960485 (2026-08-01T00:10:46Z), 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/UK2381401710.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x8fb4a571f4592f140000d82502a65d544046b69db5f48c214d5748593e28eea7. 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/SEVWU1900101.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x4ff7155ba3c68aa840018c91c92eb499cf6054f78fd989f880f3c0997e2e02ec. 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/SEVWU1900105.