thumb|right|300px|True, visible, and astronomical horizons. Not shown: refracted horizon. Most commonly, the horizon is the border between the surface of a celestial body and its sky when viewed from
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 0xbba0a4473574e0ed03fa410d12eaba4f96c801504dc9c6f1c62f94527ef77a7d. Chain 2 (Bitcoin): anchored in block 954659 (2026-06-21T06:14:42Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/dd21f210-8c38-4d2c-ab59-eb312e7b2150.json and https://artists.proofprofile.net/proofs/artist/dd21f210-8c38-4d2c-ab59-eb312e7b2150.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 0x74653b7c2d13c6e3559dc502b686429195822f9ff6bff60db6e8ea15b600d03f. Chain 2 (Bitcoin): anchored in block 958157 (2026-07-15T16:08:34Z), 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/UABM12500490.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x880d8860592359891d59922750f99a55ed7d62d3e88016699fad369c8036af44. Chain 2 (Bitcoin): anchored in block 958504 (2026-07-18T05:41:32Z), 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/UABM12500625.