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
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x5c29bdbd34004d76aea8e5b366532013f0c841a3979e7199e00e94006d71aa39. 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/ddbd9171-6585-443b-8938-23edce2dbb56.json and https://artists.proofprofile.net/proofs/artist/ddbd9171-6585-443b-8938-23edce2dbb56.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
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x559dba82865f6725da8667d6b4a2549d21bdcd7a712420f92b189a7d12c5f961. 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/VNA0M1925707.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xf406258bd67eafbe515722501dd309ac010fd530ced2cb3ff5d32a4d55352e0c. Chain 2 (Bitcoin): anchored in block 956302 (2026-07-02T03:30:09Z), 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/FR96X2129866.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x6e37d0fac0c62b47b515b36ce5c14a16b13e4b953129879fd3b59e331a14f74e. Chain 2 (Bitcoin): anchored in block 956891 (2026-07-21T09:06:34Z), 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/VNA0R2000220.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x740f794b62ae17762be9a717df9e7ae52a9c80c5a1a77626bccd3d733818abcc. 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/VNA0M1912006.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xe29117a09234a8977dc089c0810457f3e50d57b5baedf63e22b132b8e1437e9a. 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/FRX202258123.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x5bc4760390b679f2398b60d39f46b38584af0c0b17770950f0bfa97c9dcb4723. Chain 2 (Bitcoin): anchored in block 957124 (2026-07-08T03:53:27Z), 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/DGA062384101.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x740f794b62ae17762be9a717df9e7ae52a9c80c5a1a77626bccd3d733818abcc. Chain 2 (Bitcoin): anchored in block 953528 (2026-06-13T15:41:10Z), 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/VNA0M1912006.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x559dba82865f6725da8667d6b4a2549d21bdcd7a712420f92b189a7d12c5f961. 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/VNA0M1925707.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x5bc4760390b679f2398b60d39f46b38584af0c0b17770950f0bfa97c9dcb4723. 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/DGA062384101.
Truy Lùng Bảo Vật (feat. 24k.Right & Sofia)
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x4eb81505691d44d38a982493b6ab3b969e63bbf4fc93f6a69c7b755115940263. Chain 2 (Bitcoin): anchored in block 953528 (2026-06-13T15:41:10Z), 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/US38Y2300022.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xdd5c690abd0d17d1395f58f5a965aef596ce356809c2650f33dea83be6ecdc8d. 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/VNA0R2400046.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xeaf405a68d41bf7a60cb9eba6caf58a2ca316cf7a012d82e6394c7c8bb7f8cff. Chain 2 (Bitcoin): anchored in block 960264 (2026-07-30T14:36:16Z), 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/VNA0M1912007.
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 0x646af80bdcf4e816e95832da48e39f09a5f227d488f453f9d9c036f6b67dbb92. 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/VNA0M1925708.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x427a08948a42db4fa2ab873c416022433cb327a99e9e166ae0878fdf876f5b1a. Chain 2 (Bitcoin): anchored in block 960317 (2026-07-30T21:35:24Z), 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/VNA0M1926513.