Closed loop or closed-loop may refer to: Mathematics Loop (topology), topological path whose initial point is equal to its terminal point Closed curve, the image of a continuous mapping of a circle
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 0xd402b7fc0d57ebe65183ee2d5f97b0088e8253d8132d64d18ea03ed47dbad632. Chain 2 (Bitcoin): anchored in block 953803 (2026-06-15T15:41:00Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/e55f3206-d91e-43bf-9efb-067de94ef0e0.json and https://artists.proofprofile.net/proofs/artist/e55f3206-d91e-43bf-9efb-067de94ef0e0.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 0x8070ef74c907368b26c164d0efb681dfdb8f3029ba92daf882548a147e8dbdf4. Chain 2 (Bitcoin): anchored in block 956776 (2026-07-05T10:59:37Z), 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/US3DF2511684.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x2b386960d240df550e8d8916b63460b515475a8e4e28a0f462337b96a986fba2. 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/US3DF2516820.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x7c1351e3a341c1da3edad5576618d88b087dad09694e0f7797e8cf700c6671bb. Chain 2 (Bitcoin): anchored in block 956725 (2026-07-05T01:12:41Z), 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/US3DF2531141.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x37fdee10afbbcad4cf66f11b3a09db683bef5844a5c9a73275db680e6d5c276b. Chain 2 (Bitcoin): anchored in block 957759 (2026-07-12T21:46:51Z), 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/US3DF2524249.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x688dd0dbf7b08c94368d8592791cbba1a406ef048597db027c9416ea1d0082e6. Chain 2 (Bitcoin): anchored in block 958520 (2026-07-18T08:19:09Z), 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/US3DF2531142.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xf731deeac343263d8d342a3829a05b1ea85c8a7b938924c96adca89e5e626f4c. Chain 2 (Bitcoin): anchored in block 958362 (2026-07-17T04:32:48Z), 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/US3DF2540724.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x7e811484689b342f11624327768a8200bb46e5d0ed74a751f45e6df0832cb8d8. Chain 2 (Bitcoin): anchored in block 958111 (2026-07-15T06:58:20Z), 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/QZMHP2521744.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xb561f9a65bcb2f6b869767c03d0fbd9c8c5b767e0cdb022a1adf04868d0cc6cf. Chain 2 (Bitcoin): anchored in block 959103 (2026-07-22T05:56:21Z), 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/US3DF2536216.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xa234608c408f66a3ff44f4a27783c408953bf2d3ef612da94f2d9f0a85ed9c00. 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/CAQOI2506311.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x0c2808357d40c7f535ae88d7591feb727367ada063b4efa7fb429b926a077abb. 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/QZPEW2421136.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x3273de226f4f8154f9b7121fe7e3d8d506b5d803a4e2d583130e89e67588d3fd. 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/QMANG2409267.