Witchhammer () is a 1970 Czechoslovak drama film directed by Otakar Vávra and starring Elo Romančík. Based on the novel Kladivo na čarodějnice by Václav Kaplický, Witchhammer relates the story of the
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 0x2648ddb313ecebe9f917e360724b722a8afe0bef9ae4f501138495a0df5af03f. Chain 2 (Bitcoin): anchored in block 953949 (2026-06-16T13:28:01Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/1c5b50ba-4cd8-40ff-8747-a5f6df04dafc.json and https://artists.proofprofile.net/proofs/artist/1c5b50ba-4cd8-40ff-8747-a5f6df04dafc.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).