Joo Yeon Sir (; born June 29, 1990) is a South Korean-born British violinist and composer. Sir was born in Seoul, South Korea. Sir was educated at the Purcell School and at the Royal College of Music
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 0x84ddf7529f65e15ff4b70a6a5d06bc1d5a403ffbde14324cda46d2c7583222ab. Chain 2 (Bitcoin): anchored in block 953768 (2026-06-15T09:30:06Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/c33f4ecd-e376-47a2-a756-3038345e477f.json and https://artists.proofprofile.net/proofs/artist/c33f4ecd-e376-47a2-a756-3038345e477f.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).
Britten, De Falla, Gershwin, Milhaud & Schnittke: Suites & Fantasies
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 0xddfe47ae1b9770880bb01c9508070fa7c3f4621d80f78bfefbdb25bc414a4093. Chain 2 (Bitcoin): anchored in block 953515 (2026-06-13T12:53:06Z), 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/DEN961630304.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x136fb659f9d3cbfd5552664686b934b180681ec3e7f643760b6d232ea4a11c29. Chain 2 (Bitcoin): anchored in block 956304 (2026-07-02T03:55:08Z), 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/DEN961630305.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xdf7bf21ef27efd481b744624c2b4bf87195ba92f3b9d1557398b042d20ad566a. Chain 2 (Bitcoin): anchored in block 960117 (2026-07-29T14:28:24Z), 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/DEN961630306.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x7b582c6ef37095a1c38f831d8f3a1d23f86dad9eb04ed644cd9864ed70a32d0d. 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/DEN961630307.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x11fd2b2bc3d74ec25f5384aecc39c1e3d26d153ec503c4cd2f2d38e0a351efd9. Chain 2 (Bitcoin): anchored in block 960166 (2026-07-29T23:39:29Z), 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/DEN961630310.