Learning to Swim () is a book written by Sara J. Henry and published by Crown Publishing Group (now owned by Penguin Random House) on 22 February 2011 which went on to win the Mary Higgins Clark Awar
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 0x499f6493f9e4247d2def2517484a4b8c506f899e7b39f8f509793540bb7d40cb. Chain 2 (Bitcoin): anchored in block 954587 (2026-06-20T19:10:41Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/bbedec76-0c87-4e0b-a4b6-417985022f5d.json and https://artists.proofprofile.net/proofs/artist/bbedec76-0c87-4e0b-a4b6-417985022f5d.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).