Sofia is the capital and largest city of Bulgaria. It is situated in the Sofia Valley at the foot of the Vitosha mountain, in the western part of the country. The city is built west of the Iskar river
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 0xa80339965cf33defcca6331e8811308b77469208efbbcc6cc07c4427cbb36e28. 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/21272c9f-6d6a-4e26-a3bd-74de45817816.json and https://artists.proofprofile.net/proofs/artist/21272c9f-6d6a-4e26-a3bd-74de45817816.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 0x44994a161e83ab874a7e7fc06596c09e76e364bd2eef32d125947caa8cbb1070. Chain 2 (Bitcoin): anchored in block 956375 (2026-07-02T16:51:38Z), 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/QZDA62175291.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xb4422e68168d5ebd891fe892bb2c1049bc4ebb329b691ca3185fb5bb9f4a622f. Chain 2 (Bitcoin): anchored in block 958340 (2026-07-17T00:53:26Z), 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/QZES52173406.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x48559684b213a520dffef32d39de257a35b1269d355fd447d0ad922448a8d236. Chain 2 (Bitcoin): anchored in block 959001 (2026-07-21T11:41:42Z), 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/QZHN32101052.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xf085866ff0162af225069526ebd6cba96ff50bbf3454fdc753900c66f2582954. Chain 2 (Bitcoin): anchored in block 957888 (2026-07-13T17:43:59Z), 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/QZMHN2066238.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x42b6a4dfa0f4e394af3bd2baa42d795a91bbac2908a6dde21ae86eea69f86809. 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/UKW3Z2301801.
Truy Lùng Bảo Vật (feat. 24k.Right, Sofia & Hoàng LV)
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x79251f5e43c9bc4bd2a14105685439a7ce5e901410169700c5c7a58695073ab5. Chain 2 (Bitcoin): anchored in block 960203 (2026-07-30T03:35:13Z), 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/US38Y2417286.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xea3554f16ad01defa2ce0f57bf684f739056fa4804265e4c0bf32989af11089b. Chain 2 (Bitcoin): anchored in block 957067 (2026-07-07T16:54:37Z), 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/UKFTL1600286.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x44e736dc6aa6aa7b7facabe2502da0135f0db5d8f81b3409423b00482963412e. 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/GB8KE2313606.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x003cfb21e16e87f15a1d10ac79bcac321629b32cfd8c0e2101310e83c7720e07. Chain 2 (Bitcoin): anchored in block 953513 (2026-06-13T12:47:07Z), 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/GBQGW2400028.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xf60da1fdb6b1b7442e83143124a54aef09d70ed5bd0df8aa48789b3f12b7025e. Chain 2 (Bitcoin): anchored in block 953513 (2026-06-13T12:47:07Z), 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/GBQGW2400026.