Primero (in English also called Primus, in French , in Italian or in Spanish Primera), is a 16th-century gambling card game of which the earliest reference dates back to 1526. Primero is closely rela
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 0x8bb46a4c4a90472bed5f6a2711d155e20f495c7f3e861ed51103efb5e18308b9. 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/2e14d4f2-5215-44dc-be12-2f1a5f6b9980.json and https://artists.proofprofile.net/proofs/artist/2e14d4f2-5215-44dc-be12-2f1a5f6b9980.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 0xa416e3bc82af850c2b056a1c6fdc4a0b0d52a246407a3323ef21a94331b35451. Chain 2 (Bitcoin): anchored in block 958501 (2026-07-18T05:33:04Z), 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/BEEN91630002.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xed628ab035bf4887bc21cbb7d4f8517a5c39042e0e53ef867ef037e6d60624bd. Chain 2 (Bitcoin): anchored in block 956772 (2026-07-05T10:01:46Z), 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/BEEN91630003.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xe29805a7af779be3a545c4ad640dc6b0858158f06870d561dfe804177694e802. Chain 2 (Bitcoin): anchored in block 958897 (2026-07-20T14:57:46Z), 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/BEEN91630005.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x3cc0fffa1db215065247e0ffe3055050cdc75f49d7c3063f937842eaa4017cf7. Chain 2 (Bitcoin): anchored in block 958501 (2026-07-18T05:33:04Z), 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/BEEN91630006.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xb4a875eeaca9c0cebc8a73226fc0330be2795893bd817b8bad73b1c03f252fe9. Chain 2 (Bitcoin): anchored in block 956375 (2026-07-02T16:51:38Z), 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/BEEN91630007.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xbaedc26ed2504a5e727eca7725311c29c2e71e243112ad281777a935b716eec9. Chain 2 (Bitcoin): anchored in block 958140 (2026-07-15T10:05:23Z), 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/BEEN92100101.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x55eddeec4b5efe922987f5bee39367edc34d6cdede8529a69c7174168308e8ff. Chain 2 (Bitcoin): anchored in block 956375 (2026-07-02T16:51:38Z), 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/BEEN92100104.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x1d4e829def4d5d2ab6635077078d6553ead061a5cc4e8861cfb681c6d3be8616. Chain 2 (Bitcoin): anchored in block 956826 (2026-07-05T19:27:56Z), 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/BEEN92100103.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x6035afd34bbe3897ddcc7fbdff5c876d4047c6093c4cb77245725ec76ce0ef58. Chain 2 (Bitcoin): anchored in block 956375 (2026-07-02T16:51:38Z), 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/BEEN92100105.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x14b6307fb3b2fcb95a95f9e89c238df9c57f171df428c81c1b4e2f135f641628. 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/BEEN92100106.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x2a7321294fae601f2ca8b76728d370550ef60fe09e2d9088c16044e495bbc057. Chain 2 (Bitcoin): anchored in block 958508 (2026-07-18T06:27:01Z), 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/BEEN92100107.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xc84f8eed14d15beb5319589e14752e77f5b75a850bcad9f1b6ee1a7b28caa7c9. Chain 2 (Bitcoin): anchored in block 956634 (2026-07-04T10:04:33Z), 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/BEEN92100116.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xa7d40445246abcf392ba2dc13ae3b1475b304f8993ba4b4b02cc217ad5f9ec0b. Chain 2 (Bitcoin): anchored in block 956474 (2026-07-03T08:56:35Z), 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/BEEN92100110.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xd6adba95def16959c72b8a44d7b6b7b46a507792ccde86700ef62e5d7ece1a96. Chain 2 (Bitcoin): anchored in block 956772 (2026-07-05T10:01:46Z), 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/BEEN92100111.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x228264c879e051c36fe26e34a875a1fb344070ef8dc4dd869ad29ac18b61b93c. Chain 2 (Bitcoin): anchored in block 956826 (2026-07-05T19:27:56Z), 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/BEEN92100114.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xf805241c49e946d32310d517cb3f660c49f43d1cada336f81a924b4cffa6ae24. Chain 2 (Bitcoin): anchored in block 956474 (2026-07-03T08:56:35Z), 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/BEEN92100113.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x5f58e256eab73d77f0fd7b28d4a8d72cb7f1af6edd1ff648c1cc2418c746a7eb. Chain 2 (Bitcoin): anchored in block 959047 (2026-07-21T19:17:28Z), 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/BEEN92100112.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xc084993844f7b8252115478511a2561dc4c04d8c9ad44ff6684e9b55c1808f3f. Chain 2 (Bitcoin): anchored in block 956772 (2026-07-05T10:01:46Z), 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/BEEN92100117.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x9420b140650ed43ce02596f3182e90723d6bd309c5b625fd7455c7ee76cb992d. Chain 2 (Bitcoin): anchored in block 956634 (2026-07-04T10:04:33Z), 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/BEEN92300036.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x11eedda89023ff50591e956e0acbce24f9556b07549b4af823812a65d50cb0a1. 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/BEEN92100108.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xd6adba95def16959c72b8a44d7b6b7b46a507792ccde86700ef62e5d7ece1a96. Chain 2 (Bitcoin): anchored in block 956375 (2026-07-02T16:51:38Z), 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/BEEN92100111.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x228264c879e051c36fe26e34a875a1fb344070ef8dc4dd869ad29ac18b61b93c. Chain 2 (Bitcoin): anchored in block 956375 (2026-07-02T16:51:38Z), 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/BEEN92100114.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xc084993844f7b8252115478511a2561dc4c04d8c9ad44ff6684e9b55c1808f3f. Chain 2 (Bitcoin): anchored in block 956545 (2026-07-03T19:59:51Z), 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/BEEN92100117.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x297a8ec373be67504bafa4e60c3bbb1502f2518f9833360969247d9bbd6a6712. Chain 2 (Bitcoin): anchored in block 958180 (2026-07-15T17:59:52Z), 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/BEEN92100115.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x75b0c90d6e9d6b1712bc971959d8b9cdbce847ead1126e71ea2a302923af284f. Chain 2 (Bitcoin): anchored in block 956474 (2026-07-03T08:56:35Z), 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/BEEN92300037.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xb41cdb76245ad82269759a1b16006cff6439871680735dfab9639c41b336e14c. 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/BEEN91990020.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xf94672b5efaf53e0c479ce8631687fd2ad620d9242f81a3a4b716818411a9837. 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/BEEJ11710011.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x33da0015893f0a243f136b6734bc2042b8d4bedb910fb39c546e820901029dce. 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/BEKV42100010.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x0b53a4985993e48611b3fd71ecca5f177085863116ad60a5aea4630c784a52e2. Chain 2 (Bitcoin): anchored in block 957041 (2026-07-07T13:25:45Z), 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/FR9W11919462.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x7e7137bdd274fc3bbfb76a7f7882b21d7e30d74534c74ab48b35c8b8722f6f7d. 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/BE1JB2000007.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xde50e19db8ff4c48cb2800eadb6249fc7a47c22a4893113a3763546ca39da679. 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/CAH682300017.