CityZen was a formal dining restaurant located in the Mandarin Oriental Washington hotel in Washington, D.C., in the United States. Established in 2004, it served modern American cuisine. Eric Ziebold
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 0x49195bbf1bb17d612b234ea855fbd723038b400cf4734baacc4a685c079985ec. Chain 2 (Bitcoin): anchored in block 953714 (2026-06-15T00:43:59Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/85157594-fd8c-4324-87b9-31b73d63ea1a.json and https://artists.proofprofile.net/proofs/artist/85157594-fd8c-4324-87b9-31b73d63ea1a.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).
1. Confirm isrcCode identifies the recording in the pre-2022 source corpus and cc-db-prod record 2. GET OTSVerificationAPI → server-side canonical-record, hash, and attestation checks must pass 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. Confirm CopyrightID is the CopyrightChains transaction hash 5. If all match: the cc-db-prod record is independently anchored on Bitcoin at OTSTimestamp
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x47ae3034645e22236edd0c01561837f57972cea81a17aafcf2c77a91d5b32edf. Chain 2 (Bitcoin): anchored in block 956772 (2026-07-05T10:01:46Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/NLW4L1900110.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x5a8b1dab9e5a083a4c1e0dadf2445a429d4cab8513e28ef52f33c36c78af18f6. Chain 2 (Bitcoin): anchored in block 957891 (2026-07-13T18:21:04Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/NLW4L1900153.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x93dba7ab3de559684b2989d7ae8399767b1a67733ebf584fa1d890661d47c361. Chain 2 (Bitcoin): anchored in block 956772 (2026-07-05T10:01:46Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/NLW4L1900168.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xa56e3c9468b610f0a90edc4dcea8d930cc22fd1b9fd6acea5726439c660c78d7. Chain 2 (Bitcoin): anchored in block 958901 (2026-07-20T18:01:42Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/NLW4L1900183.