Chalk is a soft, white, porous, sedimentary carbonate rock. It is a form of limestone composed of the mineral calcite and originally formed under the sea by the accumulation and lithification of hard
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 0x3368bd4c92196670db315cdc46c415f4ca754c3728ce70c3593dd6ffa05f79ee. 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/81e7bd05-4a2d-4d71-9a92-b9836f0e3101.json and https://artists.proofprofile.net/proofs/artist/81e7bd05-4a2d-4d71-9a92-b9836f0e3101.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 0xef71c59557f3b5522f273ddf61b5ea68e851e9c62b08b68af6f660a359d38533. 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/GX7332382000.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xb805d3d6f2f482f5e571062ce4f07cb12d9dad1b1567e8dbf5452e3fcaf4ee1c. 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/UKJ7P2400162.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x1112748394c16724507f0db9bc7bf389f924048f2574e756d959c75a623287cb. 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/FR10S2443188.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x65638fea069f793a4ac0d77aa6278d3300510896ccf2496bad557e607404294c. 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/FR10S2443189.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x65638fea069f793a4ac0d77aa6278d3300510896ccf2496bad557e607404294c. Chain 2 (Bitcoin): anchored in block 953513 (2026-06-13T12:47:07Z), 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/FR10S2443189.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xef71c59557f3b5522f273ddf61b5ea68e851e9c62b08b68af6f660a359d38533. Chain 2 (Bitcoin): anchored in block 956302 (2026-07-02T03:30:09Z), 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/GX7332382000.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xb805d3d6f2f482f5e571062ce4f07cb12d9dad1b1567e8dbf5452e3fcaf4ee1c. Chain 2 (Bitcoin): anchored in block 956302 (2026-07-02T03:30:09Z), 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/UKJ7P2400162.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xb805d3d6f2f482f5e571062ce4f07cb12d9dad1b1567e8dbf5452e3fcaf4ee1c. Chain 2 (Bitcoin): anchored in block 953536 (2026-06-13T17:25:41Z), 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/UKJ7P2400162.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xaf72387ba1b2d7893023c7aef2b1f9798eb8d338fcc09c6bf1d336f046a1da79. 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/QZES52381004.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x52318dbe1dd326caba2e8b7d367aa904c7b523dd20723e586b35668cac90002d. 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/QZFZ32371407.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xf874b233414d0a9cd277559413d0c5d2d6550636e956c9bfd15f5115f4779568. 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/QZDA82289885.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xe61411dbb2cd7e68f822a1e34135a72b4653dcac1674ab05ccbff6b98450532e. Chain 2 (Bitcoin): anchored in block 956302 (2026-07-02T03:30:09Z), 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/QZPLR2290952.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x66af30638d47878684adfdb56aabc4cfab4fed59cde687be26ebb8a6f1f0a0ab. Chain 2 (Bitcoin): anchored in block 953513 (2026-06-13T12:47:07Z), 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/QZHN72328124.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xaf72387ba1b2d7893023c7aef2b1f9798eb8d338fcc09c6bf1d336f046a1da79. Chain 2 (Bitcoin): anchored in block 953528 (2026-06-13T15:41:10Z), 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/QZES52381004.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x52318dbe1dd326caba2e8b7d367aa904c7b523dd20723e586b35668cac90002d. Chain 2 (Bitcoin): anchored in block 953513 (2026-06-13T12:47:07Z), 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/QZFZ32371407.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xe61411dbb2cd7e68f822a1e34135a72b4653dcac1674ab05ccbff6b98450532e. 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/QZPLR2290952.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xf874b233414d0a9cd277559413d0c5d2d6550636e956c9bfd15f5115f4779568. Chain 2 (Bitcoin): anchored in block 953513 (2026-06-13T12:47:07Z), 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/QZDA82289885.