Marcelo Demarco (born February 19, 1971), also known as Mark Demark, is an Uruguayan disc jockey and record producer. He began his professional career in the early 1990s in Montevideo's incipient rave
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 0xc80205c632e7f306e385c058e85e9e42464c9e9e923b562802a5f71346d70b4e. Chain 2 (Bitcoin): anchored in block 954017 (2026-06-16T23:38:33Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/35be0f01-77a8-4953-b092-c9d4b3ce8580.json and https://artists.proofprofile.net/proofs/artist/35be0f01-77a8-4953-b092-c9d4b3ce8580.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 0xfff398ff40239d061a06ce78b31784da2ac5630b982ac3754e817dfc4b05bdf2. 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/QMSQL1500261.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x64594e20c9e75b5c8eacf8e92a6830511725221aa0731bf52b8966b3867e9a8b. Chain 2 (Bitcoin): anchored in block 957145 (2026-07-08T08:56:20Z), 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/QMSQL1500186.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xc9f8bbdf8140b4313c52a0592896ed6903d592b12f7708e360b892290e510e4a. Chain 2 (Bitcoin): anchored in block 957145 (2026-07-08T08:56:20Z), 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/UKACT2132840.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x1fa449e7ffbecd7f994d940a9612725fb32176a625fd95d14ef13e15e910f791. Chain 2 (Bitcoin): anchored in block 957122 (2026-07-08T03:39:04Z), 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/QMSQL1500133.