Optometry (from Ancient Greek ὄψις (ópsis), meaning "eye", and μέτρον (métron), meaning "measure") is the healthcare practice concerned with examining the eyes for visual defects, prescribing correcti
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 0x16587018513f8339a69d0a8aac578077610dbebc3e1004a6b4882d5ae8220597. 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/a0b2c442-463c-46cd-89d5-bb5f7d71aa87.json and https://artists.proofprofile.net/proofs/artist/a0b2c442-463c-46cd-89d5-bb5f7d71aa87.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 0x58ee166962cb4965caa4abfe6feff3cdfe40a09e3c3f921d9cf55f80015b8019. Chain 2 (Bitcoin): anchored in block 953520 (2026-06-13T13:32:09Z), 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/US3D32308102.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xe0023a713268afb4f4b5159bd31721ac4b2b6f2d3023ea2849b1aec3cb87e65b. 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/US3D32308103.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x231327a1efe5b1d09f8e52385a3912e61991d74c67b4d4c38369a560cd61e60a. 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/US3D32308106.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x6c735c33f555747cb3668dec0d174d78a31569ef354f001f2cc201d4409621fc. 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/US3D32308107.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xaa4c34eef347861e7a87dff96cdb7ae00e76c7c6cc6ca19e02653c4e3de17b70. Chain 2 (Bitcoin): anchored in block 960284 (2026-07-30T17:23:26Z), 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/US3D32308101.
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 0xa80e11f2bfae4c13f48079d6e2ca1c06caf216185fe6cf035d4b0d1bc380d972. Chain 2 (Bitcoin): anchored in block 960222 (2026-07-30T07:48:45Z), 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/US3D32308104.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x5b8cdfb22117be6307b020cd5add2e06fd336d37df954a46cfea7fd29f2c8439. 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/US3D32308105.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xa72aeb7f86527d745e60549862eaf0652a01d1d1a15660824a3a65eb9f4e8a74. 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/US3D32408501.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x78d9b706973da8b8696d1d5712c9297e91f2b4c61e62eeed2cca17cf95a7d9af. Chain 2 (Bitcoin): anchored in block 960185 (2026-07-30T01:32:48Z), 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/US3D32408502.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x2bc282b14a79b5b0951ddfa0da462b4fc1af68b5c4147ed5270176e51b77e4e1. Chain 2 (Bitcoin): anchored in block 960291 (2026-07-30T18:23:33Z), 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/US3D32408505.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x0291e8a3141f446e68748c169b53938dfb7fc74d329ed61da0685a98db42310f. Chain 2 (Bitcoin): anchored in block 953515 (2026-06-13T12:53:06Z), 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 via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/US3D32307601.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x43a101ace3b1b586fd413326447ec200bae00f7ec24c6f9fe4e065a22994429f. 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/US3D32307604.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x16343b24aca693c152fa73d8ac39ffaef8be4ff7f6b862775282db99b1907b56. 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/US3D32307605.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x67aed77b69e378c5a561ea964f11fd06044e3ec3dbe0dc009f192162f2e1a25f. Chain 2 (Bitcoin): anchored in block 956894 (2026-07-06T07:53:57Z), 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/US3D32307606.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xae7565b06f5891d96297cf9a418d4b58c5afc81dc9eefa2dac7bf2b74542893f. Chain 2 (Bitcoin): anchored in block 958042 (2026-07-14T18:24:07Z), 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/US3D32307607.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x2b862b916cbf39f9e7cd60dd470eccb2740cf1a25a7b0d89d3ce2e29447cf0fb. Chain 2 (Bitcoin): anchored in block 960138 (2026-07-29T19:35:34Z), 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/US3D32307602.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x323bdbccd4513ce66c4a7500505fbff0ecd9e924af2e8a89837171a376d26b06. Chain 2 (Bitcoin): anchored in block 960209 (2026-07-30T05:15:54Z), 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 via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/US3D32307603.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xcdd1572418c770778de20f55d8f20785920313844a15df2e65ee7058b6b2a5d5. Chain 2 (Bitcoin): anchored in block 960291 (2026-07-30T18:23:33Z), 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/US3D32307608.