David Mayoral Lastras (born 5 April 1997) is a Spanish footballer who plays mainly as a right winger. Club career Mayoral was born in Ávila, Castile and León, and played youth football for Real Ávila
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 0x8a82132c8f87af7423378f445291a1bc741ae911b1c20acb26b98f1aea65b628. Chain 2 (Bitcoin): anchored in block 953602 (2026-06-14T06:58:10Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/0f338115-3f12-44b0-bf88-38536b32e92d.json and https://artists.proofprofile.net/proofs/artist/0f338115-3f12-44b0-bf88-38536b32e92d.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).
Recitat XIV (10): "Com prolonga la infantesa i retarda la velledat" / Música: Folías antiguas (C. M. Palacio No. 121)
Erasmus - Elogi de la Follia (Versió en Català)
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 0x1e3fc40c9eb4802580ec22c8ad042f32451831f2aac42b6e02a3213fda1ad14b. 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/US6R21347943.
De Visée: Passacaille pour guitare in D Minor
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xc15197b845fdaa19ce37dafea674393453cc5198bbb52cf8d2fade282fde157c. Chain 2 (Bitcoin): anchored in block 960111 (2026-07-29T13:21:01Z), 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/GBPFW2200159.
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
Instrucción de Música Sobre la Guitarra Española, Book 2: Canarios
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x9c221a3112839afd5d75d1941be8d37f6e3fa7b7763b1fb2466914c938a1d9dc. 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/DEA291800017.