thumb|Example of a "skuf" Skuf, also known as skufidon (Russian: скуф, скуфидон), is an internet meme in the Runet (Russian-language internet) that gained popularity in the 2020s. The term "skuf" ref
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 0x48a45b85dc2681d7167f19a678dbba790f13b0aa6c068c12bea64379e37f6e27. Chain 2 (Bitcoin): anchored in block 954342 (2026-06-19T03:22:39Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/8bdc9fb1-635d-4b06-8825-ce9c7acbb9e0.json and https://artists.proofprofile.net/proofs/artist/8bdc9fb1-635d-4b06-8825-ce9c7acbb9e0.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).