The Kupa () or Kolpa ( or ; from in Roman times; ) river, a right tributary of the Sava, forms a natural border between north-west Croatia and southeast Slovenia. It is long, with a length of servi
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 0xbeb64cbba6eacb22d40ec3f37a645b78eebbbaa3eb2e82fb5616a7b2a9dfce70. Chain 2 (Bitcoin): anchored in block 953596 (2026-06-14T06:21:39Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/0aa46e7a-52f2-46e8-8518-f701d6481af6.json and https://artists.proofprofile.net/proofs/artist/0aa46e7a-52f2-46e8-8518-f701d6481af6.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 0xb5cf1b4e2061416d615d8e65d1941ac9e3d8c3d8036ec58073246bbe2d692d74. 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/TCAIL2415893.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x1cc10f13f604a7a70799a8db5585c7039d8c3e49224f9fa187d2137f20a86bfb. 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/TCAIL2409812.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x62101a8b168433b76023f77d1ba4da642fd5ad7265d28abaf27ea6e506838972. Chain 2 (Bitcoin): anchored in block 960150 (2026-07-29T21:51:49Z), 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/TCAIL2416083.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x7047af7d0457d5e645cb2819a24ffdefecd888f75479518059a3d7ee725cb11f. 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/TCAIK2416097.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x14e018e2061c4883bd3ae0059e18d245e94989e04432c5bf02509e1f9274edf4. 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/TCAIK2416112.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x811b638eff9deb8142490e45cd91a0ed3245f603c8ca838534836d05bcf83fc4. 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/TCAIL2416124.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xd75a237c57949aedce473dce1356b2ab54f686f8119f115789254c93975a1cc0. 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/TCAIL2417892.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x932bbb2606008012d29ce1d6761b713a2841944f1f510038abcc5d9936305fd8. 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/TCAIK2416179.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xdc042447983329370b80b494edc41749f1a7569115acf469f26600dda3d2db06. Chain 2 (Bitcoin): anchored in block 960327 (2026-07-31T00:26:26Z), 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/TCAIK2416299.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x1cc10f13f604a7a70799a8db5585c7039d8c3e49224f9fa187d2137f20a86bfb. 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/TCAIL2409812.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xd75a237c57949aedce473dce1356b2ab54f686f8119f115789254c93975a1cc0. Chain 2 (Bitcoin): anchored in block 957120 (2026-07-08T03:22:41Z), 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/TCAIL2417892.