R15, R-15, or similar, may refer to: Automobiles Audi R15 TDI, a Le Mans prototype racing car Renault 15, a French car Yamaha YZF-R15, a motorcycle sold in India and Colombia Aviation Rubik
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 0x2e2ec3c0e1c244ea5a7cf0f2ae1ba2951afa710160f0a146815785f0e2ea13cf. Chain 2 (Bitcoin): anchored in block 953803 (2026-06-15T15:41:00Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/ec1fbfe1-8096-4b37-83ec-052801a7662c.json and https://artists.proofprofile.net/proofs/artist/ec1fbfe1-8096-4b37-83ec-052801a7662c.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).