Alka Vuica (; born 8 June 1961) is a Croatian singer, lyricist and television presenter. Vuica is most notable for her 1980s and early 1990s songwriting work for popular Yugoslav musical acts such as
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 0xa7692670cd0e261ae0b5d35d4a1ab1ba005d4c298d336a4fbd462df740ca3d42. Chain 2 (Bitcoin): anchored in block 953408 (2026-06-12T19:28:13Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/57d57c9b-95da-420d-9981-5e6389f6a9a0.json and https://artists.proofprofile.net/proofs/artist/57d57c9b-95da-420d-9981-5e6389f6a9a0.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 0x2fb935f6169fe48bbc2d4ad636281184081b77585ac039b4091ca427f1bbe3a6. 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/HRA049939772.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x3601920ba0a635758cc29410dfada9631b80ce83f93561a3f44cbcab123cdea0. Chain 2 (Bitcoin): anchored in block 958202 (2026-07-16T00:17:40Z), 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/HRA049532808.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xb68223ec599eda5cd8b2b60b79d79dfd2d275b1be84746a6b61e211aff867357. Chain 2 (Bitcoin): anchored in block 958951 (2026-07-21T04:04:18Z), 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/HRAA42500081.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x64c0ae205301933dfb844b235b6e677e508a91c6c170086d7482d334a260b6c0. Chain 2 (Bitcoin): anchored in block 958373 (2026-07-17T08:58:07Z), 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/HRA042500733.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x64c0ae205301933dfb844b235b6e677e508a91c6c170086d7482d334a260b6c0. Chain 2 (Bitcoin): anchored in block 958601 (2026-07-18T19:27:02Z), 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/HRA042500733.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xdd1a59f29c88437350faadd085e13c8a82c4574b4c152fc12e4f0966f0c438cc. Chain 2 (Bitcoin): anchored in block 956728 (2026-07-05T01:43:49Z), 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/HRA042400561.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x37b031a6c91865845a381b40c985979e84a26d5a1f587a5fa7b756819db9789d. Chain 2 (Bitcoin): anchored in block 956634 (2026-07-04T10:04:33Z), 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/HRA042301137.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xb3c0410692936011ad1db6c69c2d1e8c038b1af30fe8efd74ccd0685a2d2ac29. Chain 2 (Bitcoin): anchored in block 956772 (2026-07-05T10:01:46Z), 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/HRA042500842.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x8d2d89734c07f0e012e95d5a3789575232383ac4d5488bec5447580c8be8f024. Chain 2 (Bitcoin): anchored in block 958335 (2026-07-17T00:58:42Z), 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/HRA042500819.