S13 may refer to: Aviation Beriev S-13, an abandoned Soviet reconnaissance aircraft project Fokker S-13, a German trainer Letov Š-13, a Czechoslovak fighter aircraft SIAI S.13, an Italian recon
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 0x71c504b795b2202a76fe730ce731ff930406ad6deea72cee3e751c233feebf65. Chain 2 (Bitcoin): anchored in block 954516 (2026-06-20T07:04:44Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/a0cd693c-5a81-40c5-8b4b-cbd28024de6f.json and https://artists.proofprofile.net/proofs/artist/a0cd693c-5a81-40c5-8b4b-cbd28024de6f.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).