thumb|Attic bedroom in Skógar, Iceland thumb|The Poor Poet, by Carl Spitzweg, 1839 (Neue Pinakothek) thumb|Attic in Berlin, Germany An attic (sometimes referred to as a loft) is a space found directl
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 0xfbb65818a7732761621faaf1980c7c713e4b508a4391075c47070f6413f6df9e. Chain 2 (Bitcoin): anchored in block 954588 (2026-06-20T19:15:05Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/ba3e449f-6fc5-4a2b-a9a5-f54986c2aebc.json and https://artists.proofprofile.net/proofs/artist/ba3e449f-6fc5-4a2b-a9a5-f54986c2aebc.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 0x211c7310723e39611307d9a8886fb832ec9055cc266b3c9cd3b407af3b2e9369. Chain 2 (Bitcoin): anchored in block 958324 (2026-07-16T22:58:06Z), 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/ES5050200460.