thumb|right|Many FREMO modules joined together to make a large layout thumb|right|Meeting during 2010 in the Netherlands with over of track The Friendship of European railway modellers (, FREMO) is a
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 0xf4badec68d3252eb6278d70edc0119275f9c6e120b00de8fa472ad6540f9010e. 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/d658c4c2-d85e-47d5-9091-a1dc1f8e3f88.json and https://artists.proofprofile.net/proofs/artist/d658c4c2-d85e-47d5-9091-a1dc1f8e3f88.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 0x97a870cdfdf53db4b7a5aa1ef6b98682f68b85ce64fa96caa2596e63c3a55cf9. Chain 2 (Bitcoin): anchored in block 958153 (2026-07-15T12:03:04Z), 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/FR60Z1501920.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x6103d7bcfdd9f53e2bcbbd4124f6ccf10cf491ddd381f7f8498c0e8348b75718. 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/FR60Z1501930.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x2695efd590530e8d51e08ef44cf0eea775aeaa26f696b1fa2e01cf7d6e015a18. Chain 2 (Bitcoin): anchored in block 958208 (2026-07-15T22:40:25Z), 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/FR60Z1501950.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x56e230ac61b4da60414e334f1f2a9c0410955de60218734a6dc63dc6368d7f4d. Chain 2 (Bitcoin): anchored in block 958690 (2026-07-19T07:14:39Z), 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/FR60Z1501650.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x174f4b53012ff7a92a55d8bcfe027d50713c5373212dbd650c5709e046ae07ff. 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/FR60Z1501990.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xcae361e9038bca78944d752e373557a6530d07658a3ea09a60b7532c8337286c. Chain 2 (Bitcoin): anchored in block 958058 (2026-07-14T20:20:34Z), 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/FR60Z1502000.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x3f998e526000b1569ba9dd69b16f0c5cff07650309e72737993394679fbd53f9. Chain 2 (Bitcoin): anchored in block 958594 (2026-07-18T18:05:01Z), 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/FR60Z1502010.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x7fd14908bb8554f6ecaef91c95c02ca6ee69ff96692e13e13b9de5f309b31aa3. 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/FR60Z1502020.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x0ff604c9f347c8be039a665b47d4243a076663bf183d6ba67cef2d502f7fb20a. Chain 2 (Bitcoin): anchored in block 958300 (2026-07-16T16:14:30Z), 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/FR60Z1800840.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x6648aab5978a70489b7f23fa9edcfb783b4f7f11ab4552cb2affcd492aa61559. Chain 2 (Bitcoin): anchored in block 958063 (2026-07-14T21:07:34Z), 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/FR60Z1800850.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x7398e87d99eb1a54e97ee1c876a3fa8d1de630ba804d9b58d0ee8985a45aac2d. Chain 2 (Bitcoin): anchored in block 956856 (2026-07-06T01:25:57Z), 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/FR60Z1800870.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x9730af78d13d14d077752ad77e5900e5e0b1f6c6a1d2b2c72606eee3f80153f4. Chain 2 (Bitcoin): anchored in block 958700 (2026-07-19T08:09:50Z), 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/FR60Z1800910.