SPM may refer to: Places Saint Pierre and Miquelon (ISO 3166-1 code), an overseas French territory Salón de la Plástica Mexicana, an art museum in Mexico City Salsali Private Museum, Dubai, UAE
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 0xfe7b8e9f1a1c24fd6f48babe9e53b6d96925f9bb524d93a1e799855cbfcfa5a1. Chain 2 (Bitcoin): anchored in block 953909 (2026-06-16T07:53:13Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/0e9d6704-8408-4752-b9a7-91fe26c57716.json and https://artists.proofprofile.net/proofs/artist/0e9d6704-8408-4752-b9a7-91fe26c57716.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).