The Crossover is a 2014 children's book by American author Kwame Alexander and the winner of the 2015 Newbery Medal and Coretta Scott King Award Honor. The book, which is told entirely through verse,
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 0x663d2c5fc586b39cd679c4e6a3ea86926485f89c23ad7b9661b21f49c47bf22b. Chain 2 (Bitcoin): anchored in block 954689 (2026-06-21T10:35:31Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/e32c1015-4edd-4483-9a49-8353d44fccfa.json and https://artists.proofprofile.net/proofs/artist/e32c1015-4edd-4483-9a49-8353d44fccfa.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).