300px|thumb|right|A doctor visiting an elderly patient, near San Antonio, Texas, in May 1973 A house call is medical consultation performed by a doctor or other healthcare professionals visiting the
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 0x26a985999dea454367af1e1c32d6c98811caf2d179659e0b63a550d1467e290d. Chain 2 (Bitcoin): anchored in block 953423 (2026-06-12T21:20:00Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/334d391d-2339-4348-b97f-c63ab2fddb1d.json and https://artists.proofprofile.net/proofs/artist/334d391d-2339-4348-b97f-c63ab2fddb1d.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 0xf3a3a4f4f027717a275312526df154191c8416b0c0018299da70f988f329247d. Chain 2 (Bitcoin): anchored in block 958444 (2026-07-17T19:12:23Z), 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 via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/CA5KR2234815.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xcd386549a36b83e5cc1da24d3f8077190a68202cd60c007534e45f340e126f0c. Chain 2 (Bitcoin): anchored in block 956312 (2026-07-02T05:09:12Z), 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/NLRD52264037.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xcf0a6df57f8a5472afa702c888c88a9a7a40691314448f9d99e6a8fe0452ff9e. Chain 2 (Bitcoin): anchored in block 957145 (2026-07-08T08:56:20Z), 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/NLRD52264036.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x37b227a251ee07e0d93a6fc4156d0baf340eb63c13f264b20e5f448088deb544. 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/NLRD52264035.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xefb45ef5883193fa8c9bd3d94151bb22eba7a1bcd03654fbebcddc9a8ee5b9dd. Chain 2 (Bitcoin): anchored in block 957124 (2026-07-08T03:53:27Z), 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/NLRD52264038.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x52d791cb23d5dd16894099682ae5c13ccf13e7d0fec0eb73fbaa48b2c07a1921. Chain 2 (Bitcoin): anchored in block 957120 (2026-07-08T03:22:41Z), 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 via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/NLRD52264033.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xd6525bd868d78f527dc47156dacf15410f2a57eb9e8c13f7c7f5aa55b3f1b10b. Chain 2 (Bitcoin): anchored in block 957120 (2026-07-08T03:22:41Z), 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 via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/NLRD52302416.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x2f390b4fa5f284addb71afc5b7312a781c898ddfa81ecc7430e72bf2f464dd54. Chain 2 (Bitcoin): anchored in block 957124 (2026-07-08T03:53:27Z), 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/NLRD52302417.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xb79a7efd152246909533c63f997b45b5e50f20210e00da5ae3aacc7917ac288c. Chain 2 (Bitcoin): anchored in block 957120 (2026-07-08T03:22:41Z), 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 via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/NLRD52302419.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xaebd3482836e3c02111503181aeda1854fd72210e8b29f1bfe2464905de29eb9. Chain 2 (Bitcoin): anchored in block 956351 (2026-07-02T11:38:34Z), 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/NLRD52319376.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x8dce2c88915d8a1e172d6630b6811b0c4887bfaddbc5e919b84d1f978d97d7e0. Chain 2 (Bitcoin): anchored in block 957124 (2026-07-08T03:53:27Z), 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/NLRD52319377.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x5e6cbac62b01f9570fabf626171581a700e074d40f6e5ac296caac5c41239d84. Chain 2 (Bitcoin): anchored in block 956995 (2026-07-07T04:27:57Z), 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 via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/CA5KR2187138.