David Freiberg (; born August 24, 1938) is an American musician best known for contributing vocals, keyboards, electric bass, rhythm guitar, viola and percussion as a member of Quicksilver Messenger S
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 0x5bd6194a718f9d92bcf1b9cb0b9d14033322293e8a65833dc2758ce88926849a. Chain 2 (Bitcoin): anchored in block 953741 (2026-06-15T04:44:49Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/9c625c13-b4f2-4f43-b59a-054b0ba777d2.json and https://artists.proofprofile.net/proofs/artist/9c625c13-b4f2-4f43-b59a-054b0ba777d2.ots, the client at https://opentimestamps.org runs `ots verify -f record.json proof.ots`.