Unionen is a Swedish white-collar trade union. The union was formed on 1 January 2008, when the Swedish Union of Commercial Salaried Employees merged with the Swedish Union of Clerical and Technical
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 0xeeaaee655be3d3d1f92c3ea2206d90f54fadea89157f19ad307be57ca1c9f47a. Chain 2 (Bitcoin): anchored in block 954500 (2026-06-20T04:47:29Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/9b6806a1-4000-4ee6-99bc-bd3e6c0de42e.json and https://artists.proofprofile.net/proofs/artist/9b6806a1-4000-4ee6-99bc-bd3e6c0de42e.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 0xbcfde7b0e9d6917868a9e67de7a98008e98c78bcfe6484ccd6f641015707fc59. Chain 2 (Bitcoin): anchored in block 958951 (2026-07-21T02:01:41Z), 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/FIWJZ2400064.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x8d4e3b1e2431749f87a96f343bcce582b35a81d25b9f06e1af078d5cfa8ac3e8. Chain 2 (Bitcoin): anchored in block 958607 (2026-07-18T21:01:11Z), 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/FIWJZ2400065.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xae0182a82a2c5623974662735114a93e3c07c79f0d1d4d261ca4ea8b77470b0f. Chain 2 (Bitcoin): anchored in block 958256 (2026-07-16T07:22:18Z), 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/FIWJZ2400067.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x780ecd8ffc5e8b3aaa2dffdc8fde7ccfff92225ba468c48ef1f01cc4e281c9d8. Chain 2 (Bitcoin): anchored in block 958444 (2026-07-17T19:12:23Z), 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/FIWJZ2400068.