The Kalin Twins (born February 16, 1934), also known as Hal and Herbie, were an American pop singing, songwriting and recording duo, formed in 1958 by twin brothers Harold Kalin and Herbert Kalin. The
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 0xc77a381a247d82cdf48ce034be3577cad67f09a8ce37358a5abd053b9b338202. 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/fb8cd30b-0500-446d-be81-6b041ef2530b.json and https://artists.proofprofile.net/proofs/artist/fb8cd30b-0500-446d-be81-6b041ef2530b.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 0x3fe300d3414fe42cb0a5b8f5d2446e55efdf8d1c9d36a9cfaef8215efb21a3cb. Chain 2 (Bitcoin): anchored in block 958180 (2026-07-15T17:59:52Z), 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/DE1A32128125.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xf3d4e7727c23c9863225e906a2db2cc324cff2022647f3b026399758f4f6cda7. Chain 2 (Bitcoin): anchored in block 958621 (2026-07-18T22:59:44Z), 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/DE1A32128133.
The Classic Decades Presents - Kalin Twins
Monumental - Classic Artists - The Kalin Twins
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x118da02d912a74ebee954c8613ee47b679c66800b82fdaabdda890d9c2a614b0. Chain 2 (Bitcoin): anchored in block 958404 (2026-07-17T11:34:58Z), 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/QM6XS1575003.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x90d28e1dc6eb377ba22843c7d2f82792ea99881cf543b1ddb11adddad693c2bc. 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/UKU6H1942322.
Oh! My Godness - Rockin' with the Kalin Twins
Echoes of Summer - Kalin Twins' Harmonic Rhythms (Remastered)
Essential Classics, Vol. 302: Kalin Twins
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x6f846ed9db86388b9acdf3d1077958c0d0ecd7b58825d291e8ccc1ff3ad9b20c. Chain 2 (Bitcoin): anchored in block 957052 (2026-07-07T14:50:41Z), 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/GBAYE9000445.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x984c9345ba4ad0aef5e60eab629d5757105cd44afeeb8f34b5233ca3ca8aa1ae. 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/GBAYE9000453.