V21 may refer to: Autovía V-21, a road in Spain Fokker V.21, a German prototype fighter aircraft ITU-T V.21, a modem standard Tamsui metro station, in New Taipei, Taiwan Venture 21, an American
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 0x15de792ac0451b9797beb6092fa677bd91e8f16e0741fe1fd5c8b2e0b4d3c7b7. 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/f90c600b-04c8-4249-aa14-93719ed48533.json and https://artists.proofprofile.net/proofs/artist/f90c600b-04c8-4249-aa14-93719ed48533.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 0xc3c374d026249c0c165a3a7d4db5ee8bb4b902d8638b4e5119c4a90767e3d8f6. Chain 2 (Bitcoin): anchored in block 958985 (2026-07-21T08:39:15Z), 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/AEA0D2029764.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x36ee6ea2757fc15ba977aae90b9fbcdc4c5f25720db0e718d8a4168c032f10e0. Chain 2 (Bitcoin): anchored in block 958455 (2026-07-17T21:28:36Z), 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/AEA0D2029769.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x67e3fe3cde6455a9fb5907c25d2a54b7b9cac960ef2a4b34f89c9173e1fa8ef3. 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/AEA0D2029770.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xcf2f062310714eff51c3eaf455a6b1e9934216e6ff3a020589cff7aae6495f06. Chain 2 (Bitcoin): anchored in block 958942 (2026-07-21T00:24:07Z), 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/AEA0D2029771.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x41accbe7afce13eb29d69f501ad33514df4b7519740bcea216b7dc77cc2ba739. Chain 2 (Bitcoin): anchored in block 956422 (2026-07-03T01:01:38Z), 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/RUA1H2108519.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x9df9a94cd08abda041c191a07356d1322e888cc19683078bf199ec1f3eba0400. 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/RUA1H2117393.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xea4a7572d9d476e6eccb1f45763b7e9593b3341d3056db6be98dcb9017f4029e. 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/AEA0Q2145606.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xbc268372a0c79f6b5526a499e510ed269b56a6766f4c526078a9da469a547863. Chain 2 (Bitcoin): anchored in block 958796 (2026-07-20T00:01:46Z), 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/QMDA62182580.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xb05b12659c4c4038775fdfa04ab33918d9e134633d2c870c502bd54c891df8a2. 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/RUA1D2213404.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xf4dbef06c2f2e5a3d382f0db0de10be823e439ed36f407bf8a11925ddcdda726. Chain 2 (Bitcoin): anchored in block 958489 (2026-07-18T04:13:26Z), 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/RUA1D2259337.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x78fb567ce093fe776efc46796693426d90bc2615e19159b23327d301ccf4b90d. Chain 2 (Bitcoin): anchored in block 958218 (2026-07-16T00:33:33Z), 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/RUA1D2267903.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x47eee52cdbd95fc9db2fd02b17b83beccc019df0b1539322e551145338cf186f. 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/RUA1D2278713.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x8405cce1f1f752bb2a4122a39617bb5fe6f80ec6f3c25d209b63374b5c947b1f. Chain 2 (Bitcoin): anchored in block 958800 (2026-07-20T00:52:19Z), 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/QMFME2248892.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x1aafd7e008d7a3097b895b10a2e6fc6dac48bb9be43a57eae54b1abf526d1eb5. Chain 2 (Bitcoin): anchored in block 958447 (2026-07-17T19:47:19Z), 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/QMFME2310016.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x4b7b8c11c2011d0a823dd65137ec853e3944e5759e59178606f21e54b7ff5ea1. Chain 2 (Bitcoin): anchored in block 958563 (2026-07-18T14:29:03Z), 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/QM4TW2581801.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x5a4e24f5bb02923d200ebc8cd4fdc7e6817e95d6ee72033cee057e2e1618f10b. 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/QM6N22505472.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xecfa492b4aa69f0a508e8a5a105e026f90a00eef059d102e557efcb8dd8f688d. Chain 2 (Bitcoin): anchored in block 957780 (2026-07-13T00:36:44Z), 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/QM7282572810.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x07b3a75704a80ee3ecbce24fa3d5aed51f6413a5d9b481871e3f00968eda4a2c. Chain 2 (Bitcoin): anchored in block 956889 (2026-07-06T06:56:49Z), 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/QM7282572811.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xa250335443688f16e73962f957b10ef2b4d37b0583fe829fab3518e8aed66689. 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/QMDA72523195.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xbe157a0570d36d6ea49a993003a77cdc7f4798cbb5a88de417c3c680ba6ad353. 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/QMFME2501753.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xebea51ef3c219af7dee46f53acb4b8b1284accf967149acfa6e5da106d1ae516. Chain 2 (Bitcoin): anchored in block 958251 (2026-07-16T06:29:25Z), 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/QMFME2533259.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xa4931e1777b7e04f1d70f7c0cadd0b9a2c620527ac4c8c1ce9372a1dc38788a4. Chain 2 (Bitcoin): anchored in block 959128 (2026-07-22T12:33:25Z), 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/QMFME2533260.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xd0020d3f0fcc0d78803a5d88ca2a178ba0e4517abdca1594ddb17ec9f7ac9e88. Chain 2 (Bitcoin): anchored in block 957785 (2026-07-13T01:55:31Z), 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/QMFMF2524157.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xfece4d8877c8a06ef8e0fe6ad59525b5041f82a9bfb5eacd229a966ab59aad02. Chain 2 (Bitcoin): anchored in block 958857 (2026-07-20T09:45:25Z), 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/QMFMF2524158.