The Castells were a male vocal quartet from Santa Rosa, California best remembered for their hits "Sacred" (No. 20 in 1961) and "So This Is Love" (No. 21 in 1962), both released as singles by Era Reco
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 0x396f2499fa3b99e8736c68c94c1c1833f9dce2b284d6386c4e430c6268da2aca. 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/b641b71f-28ae-4a97-805a-ebdcea8d3ed2.json and https://artists.proofprofile.net/proofs/artist/b641b71f-28ae-4a97-805a-ebdcea8d3ed2.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 0x1460e68254647adb77f4e1a5bfa570c84eb1d0c8bbf1b5f72630d1f5928d3ba8. 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 via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/GBXHC2037519.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xceaef72479885512f3d10a3d17c4a001d7c136fe76b553125d2a8c105a5bb46d. Chain 2 (Bitcoin): anchored in block 958349 (2026-07-17T04:55:24Z), 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/GBXHC2037521.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xf419d6ee8ada041cce85c5a4dc47d02a9592313ecdb9e7d4a3ffe24597d2b1e6. Chain 2 (Bitcoin): anchored in block 959047 (2026-07-21T21:49:25Z), 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 via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/USDEI6205173.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xd04b1af8b8b90bef99a5e24f917289ac590690a18e73ff126d412764eadcf1f2. Chain 2 (Bitcoin): anchored in block 956500 (2026-07-03T13:55:21Z), 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/USDEI6105164.