Pressa was an International Press Exhibition held in Cologne between May and October, 1928. As German exhibitors were barred from participating in the Exposition International des Arts Décoratifs et
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 0xe9d39a3ca3c2d0b52c87c63a1db0e45254fe0969c2b72ef15944650c6decf4fe. 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/4f142ac5-3cc7-4c23-8345-cb6dee77096e.json and https://artists.proofprofile.net/proofs/artist/4f142ac5-3cc7-4c23-8345-cb6dee77096e.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 0x70e412292a03180210c15237801d0b08f7fe0b7af1accc51afc95321acd9d622. 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/TCADC1747816.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xa5bf61c0f4aa16a457770cc8301e7457f19b599118adb0747568589551ee76bb. 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/CBAWA2100001.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xa86fe3b762d2a935b97100f8e0daef3cb63aeec255bbfcb08621bf845bc927fa. 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/CA6262102003.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xcf2e6285fe5b3386573692ca04e4ef36b02eff707d9b959dbaae17db6b7397d5. 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/GBUM72302295.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x8fa46086e7944bc9f798c08c17dd9fd5711ffe202eaf0a0199549f4e2a54d56d. 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/PL2DY2200035.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x590c686b80f7ab401ff3476fdd126464390cd79ceb500fbca93c491eab350759. 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/QZDA61914621.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x3346c9f1c0e50db29cee42174894af204f4b5e7d5f704ea77d8a0857291f75ae. 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/FRX202364271.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xdeac045ce82018258a93a9eed93398cc36671e53ad5d4c825fe2bafea5ebecee. 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/CA6262202005.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x356f89a4f8a835d0cf04a5881df881ab93a10969cf39f18fda2af68ddd01907f. Chain 2 (Bitcoin): anchored in block 959128 (2026-07-22T14:55:18Z), 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/CA5KR2153371.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x770ab74af06ced6acee842068e5b63d695e96caaa87532d800cdfee52e9282bf. 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/QZAKB2345936.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x2c548c62c323b478d055ae9bc0792ebcfece9f8d05ed3d47b2139c2b6b4328c1. 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/CAW112000200.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x4f6729543e9e3f8819cbaf26ac6b74291567ad930eb01c3e2c0a232074a2fba7. 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/CA5KR2410510.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x46646d4e466d056393ab12807117ac2c44eca7000a7cb251a93c4bc17055cf6c. 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/CA5KR2410514.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x9b1b4d4560264bdffe88f255d5a7b9b7f8704464c1a408a1cd3a09a3f5c60566. 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/CA5KR2410515.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xa4ca1f6c6cef3abea3d6fede3e5279c8ada2f8c922a5ae448c385e6e37b5e9ba. 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/CA5KR2215272.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xa4ca1f6c6cef3abea3d6fede3e5279c8ada2f8c922a5ae448c385e6e37b5e9ba. 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/CA5KR2215272.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xd82e473f3b5da430de3246c2826bbc2ad8bc33c4dacdd82a1838f00d6ca0e56e. 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/QMCE32100669.