Milton Cardona (November 21, 1944 – September 19, 2014) was a percussionist, vocalist and conga player from Mayagüez, Puerto Rico. Milton Cardona made well over 1000 recordings, nine of which won Gra
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 0x0c85855b5ad8e2e151f8439b7ea9d6e72932193c7babc5807875de5af2954dad. Chain 2 (Bitcoin): anchored in block 953670 (2026-06-14T18:07:12Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/58ffffd8-ca1e-4911-b0ed-88465978d104.json and https://artists.proofprofile.net/proofs/artist/58ffffd8-ca1e-4911-b0ed-88465978d104.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 0xcc8ece310f3f9c8f3a5adf9b9280344c9034fc2eba92517001419ca183ebdf0f. Chain 2 (Bitcoin): anchored in block 956725 (2026-07-05T01:12:41Z), 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/USSYN0557502.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x5f3d57088676be58f1f131821a02969df03ad2fb3880a1b0a53c9e1011ba0f50. 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/USSYN0557503.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x283a1f6f3e21d1e6f26e912ff5ddc3fe7130e0adbc8e87ff17cd67977c29dc5d. Chain 2 (Bitcoin): anchored in block 956822 (2026-07-05T18:48:28Z), 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/USSYN0557504.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x915cc138af2189838d9cf6483af8a1f27c4df1974151f174fcc578886504cd62. Chain 2 (Bitcoin): anchored in block 956856 (2026-07-06T01:25:57Z), 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/USSYN0557506.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x525a24ee1d99acf0881b8492701c501e2aeb01f8768709c227c2f980299c1233. Chain 2 (Bitcoin): anchored in block 956576 (2026-07-04T02:06:47Z), 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/USSYN0557508.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xf3de0d791b952171a6c895f9d066d0055bf4cb1c27663afe445be110bda96644. 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/GBKQU2076305.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x294e1ca49e56bd26b92b218b3de06cf48b528e4b7e19ff08cc4e1cc8f96cb71c. Chain 2 (Bitcoin): anchored in block 960259 (2026-07-30T12:51:24Z), 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/GBKQU2076308.
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