Fiona Sit (; born 11 August 1981) is a Hong Kong singer and actress. Early life In an interview with Hong Kong newspaper Apple Daily in 2006, Fiona Sit revealed that she has always been interested in
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 0x19ce1327576e0415e2cbc37651326e12d66062b7b94185e1dd5dbbb436c6f0ee. 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/33b89fe1-27a6-4985-8200-82d15b88227d.json and https://artists.proofprofile.net/proofs/artist/33b89fe1-27a6-4985-8200-82d15b88227d.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 0x9091de8153189098628ff69f5f805e1d6f75ddf281b31ea98482c5af44734a66. Chain 2 (Bitcoin): anchored in block 953520 (2026-06-13T13:32:09Z), 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/FRX282426033.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x81f422767cf23b5da8d99b5c6e0c6a32180e360f1378df134ac465c8259bb028. 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/HKE672200102.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x7b49eced2b3b775155924baf21e0929ca5ec3915c7a9c026ee344861a2dea244. 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/FRX762313461.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x76dda2c4fc5aac9f5322141ff74839378390359db9438696acc249d5ccb0f722. 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/HKI490457103.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xd9fb207d2890f01b71500fa1a796313847f20eb261884f56163fbb99c874828a. 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/FRX872332325.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x515d0bdde4a4319fe3d7f16705597ba04eaba57e0e8091bf6fe9e5413d404a74. 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/FRX452321208.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xabd78acad979ce933f47ae528518ed3cde285e3793f19c2e7ed34be39cf32ffd. Chain 2 (Bitcoin): anchored in block 957061 (2026-07-07T16:07:00Z), 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/DGA052306438.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xf929497d4223cc6288792e876c19369972cfc96cee9eec9e8a01252d9e26557d. Chain 2 (Bitcoin): anchored in block 960276 (2026-07-30T16:01:17Z), 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/DGA052306441.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xe73fa7c3276314f398ecbbe56c350cb31d6d004b381478299fb9dda8f158e5d6. Chain 2 (Bitcoin): anchored in block 960435 (2026-07-31T16:33:26Z), 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/HKI490857209.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x404b2ef839834ecf1076a4c3ae599c227c62bda5247caeb096414789656ab9de. 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/HKI491557210.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xc2e0626bf4ceab6e805c4ed10a89b65d2377ae24f135c2757c24275d8cfd3437. 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/HKI491557201.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xbff745ce6f6a22f1dc8224f9ceb7aaa8ce6e704823b7d3382e2a9aa4bf2c0dcb. Chain 2 (Bitcoin): anchored in block 960284 (2026-07-30T17:23:26Z), 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/FRX282396938.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x4e1be68fa9e303d60eda007f4a35f29b42b5246168032020ad0c4384f5e39587. Chain 2 (Bitcoin): anchored in block 960321 (2026-07-30T22:27:30Z), 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/HKI491257104.