thumb|330px|Multiple iwans and tiled domes of the 16th-century Persian-style Mir-i-Arab madrasa, Bukhara, Uzbekistan An iwan (, also ivan or ivān/īvān; ) is a rectangular hall or space, usually vault
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 0x0a3f6a7e95cc2762b03b6221957eee2e7570887f4b0f4a7678a8ac1e78a9b91c. Chain 2 (Bitcoin): anchored in block 953592 (2026-06-14T05:36:59Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/07197ff6-e72e-47be-ba57-865cca95b46b.json and https://artists.proofprofile.net/proofs/artist/07197ff6-e72e-47be-ba57-865cca95b46b.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 0x7cb474c37b513ae70ac286dd4111c980db2324ce44c4102328c38ad79d8e44d6. Chain 2 (Bitcoin): anchored in block 958202 (2026-07-15T21:23:21Z), 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/DGA0S2469293.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x74672dc4abf61ed0141bf0cd6a23f31cee33be2ad3f4c07e092618d97198d670. 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/DGA0S2469295.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x3cffaa45c401e4e3d327f52a8ca7154d8959187aea88b58183b3061943bc8096. Chain 2 (Bitcoin): anchored in block 956822 (2026-07-05T18:48:28Z), 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/FR2X42554282.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x3b47b304ce1d806100b64f2420279d563d2b6566717738f02e331c0e69a85873. Chain 2 (Bitcoin): anchored in block 958263 (2026-07-16T08:19:47Z), 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/FR2X42554283.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x1a09284d9cc678a681f7ce757d076e8e7d581959b6d573f7525931d86c1e8de8. Chain 2 (Bitcoin): anchored in block 956637 (2026-07-04T10:56:23Z), 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/PLC062516705.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xfa70ca60030ab57aa8389c9a502c8813f2d5d970ece8c5659a272e0458216246. Chain 2 (Bitcoin): anchored in block 960448 (2026-07-31T18:48:12Z), 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/PLC062402351.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xcf21ab5bc211f3d4da3b25d66a0ba2ac8b8a056a4497722b1dc2d0a17455154f. Chain 2 (Bitcoin): anchored in block 957118 (2026-07-08T03:20:19Z), 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/PLC062402347.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x49239e222b48b8d67282e8c5fb0fcc53fa5a97326a4dfb9df8aa238591a5fcfd. Chain 2 (Bitcoin): anchored in block 960273 (2026-07-30T15:42:38Z), 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/PLC062403886.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xfc45933441773f767ba7bf77135d1603fbbdf95ebb07c54fdbf85de043c30774. Chain 2 (Bitcoin): anchored in block 960218 (2026-07-30T06:57:05Z), 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/PLC062403882.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x434951af1820d474f612b3075118fe19633e6feb431088d696f0aea191a5c7be. Chain 2 (Bitcoin): anchored in block 960150 (2026-07-29T21:51:49Z), 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/PLC062402350.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xfa70ca60030ab57aa8389c9a502c8813f2d5d970ece8c5659a272e0458216246. Chain 2 (Bitcoin): anchored in block 960327 (2026-07-31T00:26:26Z), 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/PLC062402351.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xe2f032b532e6d552225c22f64232f7dd528cd820c73a55219510c55dc7f7c7cb. Chain 2 (Bitcoin): anchored in block 960418 (2026-07-31T15:20:15Z), 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/PLC062402352.