Marta Sánchez López (born 8 May 1966) is a Spanish singer. She has sold more than 10 million albums. Biography Marta was born in Madrid, Spain. Her father, Antonio Sánchez Camporro, was an Asturian
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 0xf35e42b4053a8f2f5641565af7b8c92e7cd515963626516b414796f1fc21f16a. Chain 2 (Bitcoin): anchored in block 953714 (2026-06-15T00:43:59Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/84da094b-5697-4c4c-b9c9-aac2fac4cbe1.json and https://artists.proofprofile.net/proofs/artist/84da094b-5697-4c4c-b9c9-aac2fac4cbe1.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).