The Window Shop (1939–1972) was a store located in Cambridge, Massachusetts, created by a small group of women wanting to help immigrants fleeing Europe. It was originally located in a room on the sec
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 0x54919e2d5ff25615b3602ce463b64f5eb0f68899b2772414f47dfec24c4b9fbd. Chain 2 (Bitcoin): anchored in block 954097 (2026-06-17T13:13:51Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/7b695533-150d-4ce5-8138-3be57b936d63.json and https://artists.proofprofile.net/proofs/artist/7b695533-150d-4ce5-8138-3be57b936d63.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).