A back door is a door in the rear of a building. Back door may also refer to: Arts and media Back Door (jazz trio), a British group Porta dos Fundos (literally “Back Door” in Portuguese) Brazilian
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 0x84dfdca32de191ea3c7992dbda16c087ef510cfc19a977c3e1958a4e358ae2c1. Chain 2 (Bitcoin): anchored in block 954342 (2026-06-19T03:22:39Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/81016d40-1eac-4566-bbb6-276f945b4fe5.json and https://artists.proofprofile.net/proofs/artist/81016d40-1eac-4566-bbb6-276f945b4fe5.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 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 0x45e98cd6cd8bcdd50ba86e9184c98c1ece8459610815a883c7a68bd3825e92ea. Chain 2 (Bitcoin): anchored in block 958931 (2026-07-20T21:15:01Z), 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/USWB10001639.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xa04469efc732f49126a32cefd13e00c17b7575e77cf575a70ce178b26ce8c36a. Chain 2 (Bitcoin): anchored in block 956822 (2026-07-05T18:48:28Z), 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/USWB10001644.
Live at Impulse Studios / The BBC (2025 Remaster)