Humberto Vicente Castagna (June 11, 1942 – October 15, 2019), better known as Cacho Castaña, was an Argentine singer, songwriter, pianist and actor. Born in Buenos Aires, he initially worked as a shoe
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 0xb7357bc90250d08edbdaaf8bf2498833bad39c18727aca022072a2c4fc6fb4d2. 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/e9cb9cd6-bc12-4a36-9257-cb580d3903ac.json and https://artists.proofprofile.net/proofs/artist/e9cb9cd6-bc12-4a36-9257-cb580d3903ac.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 0xd79eabe382d85b6aacd337865f5b96a66df6068b5c68dc75eeb705e256046ed0. 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/USA560307106.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xaff8a72768936304a1cbe32b487b9b38cc5cdd9a930ce62fa76f19c15e8d841f. 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/ARF109900052.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xafd0db874a0b753557a063502e8b4d29ccb22ba9bb604e65c4d8f1cb40f7e60b. Chain 2 (Bitcoin): anchored in block 960236 (2026-07-30T09:37:10Z), 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/ARRDJ1400011.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xbf903c50e245cf34f762e29f87698c0a3ededc610b4f6a8fd1d12405a25e07b7. Chain 2 (Bitcoin): anchored in block 960441 (2026-07-31T17:29:52Z), 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/ES7350910345.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xf391540d1152139f56545b2d92e5f67ff642e1fb30888b8f54d4768cc5ebfddb. Chain 2 (Bitcoin): anchored in block 960276 (2026-07-30T16:01:17Z), 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/US3DF2029580.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x4fdbd57f263086f815ada2e321d66752415a73b1ed7250a801ec3af2e7c1385e. Chain 2 (Bitcoin): anchored in block 960379 (2026-07-31T09:25:34Z), 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/ARF050600116.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x04a31ec37e758d58ac9d793c206525dfe6d2ddd492233c4455afcfaa32cd51ce. 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/ARG991029401.
Cacho De Bs As - Live In Buenos Aires / 2016
Cacho Y Sus Amigos: Concierto Inolvidable (Live In Buenos Aires / 2016)
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x59124fc9d882e6a002ed8a25f718449b317b1104551c8a0c81fe2db0840423af. 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/ARUM71700047.
Todavia Puedo - Live In Buenos Aires / 2016
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x364b1c56c92a74bc2e5eca27fd237fb7bfb1c2255119f913e7811e83350cf643. 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/ARUM71700048.
Que Tango Hay Que Cantar - Live In Buenos Aires / 2016
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xbad727ff31babeb03b7ee9d5444e7e6413567da448465bffac5cc86b84cb62f6. 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/ARUM71700049.