SIP or sip may refer to: Places Šip (Pale), Bosnia and Herzegovina Šip (Višegrad), Bosnia and Herzegovina Novi Sip, Serbia Simferopol International Airport (IATA: SIP), an airport in Crimea Suzh
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 0x23bede1b7920d3694c0341cb8e1581b386492f2ee0f1697b7dabeb5a5342a8b0. Chain 2 (Bitcoin): anchored in block 954055 (2026-06-17T05:51:24Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/4362f357-3631-40e8-857c-9939e685f160.json and https://artists.proofprofile.net/proofs/artist/4362f357-3631-40e8-857c-9939e685f160.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).