Peter Holtslag (born 1957 in Amsterdam) is a Dutch recorder and flauto traverso virtuoso. Holtslag studied recorder at the Sweelinck Conservatorium in Amsterdam (now Conservatorium van Amsterdam), Fr
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 0x67ad1f7b386e894f93d3f313b402344415af6f7ed387d72e43ed5ccf97fc58fe. Chain 2 (Bitcoin): anchored in block 954553 (2026-06-20T11:51:30Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/abad9823-afa4-4982-bb15-16ad916baf84.json and https://artists.proofprofile.net/proofs/artist/abad9823-afa4-4982-bb15-16ad916baf84.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).