Last Word is a radio obituary series broadcast weekly on BBC Radio 4. Each week, the lives of recently deceased famous people are summarised with narration and interviews with people who knew them. It
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 0x70b94bd6320e1b6d3e5688ea00ff5ce98d069f6c7eb31a6e8e1b687f75dca1e8. Chain 2 (Bitcoin): anchored in block 954717 (2026-06-21T15:47:51Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/f564b9c3-4078-4e2a-80c9-44689dc69044.json and https://artists.proofprofile.net/proofs/artist/f564b9c3-4078-4e2a-80c9-44689dc69044.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 0xf0a2e494ba5e21c4283aca9675f6749a1397345008496c34f3719feb1b32872d. Chain 2 (Bitcoin): anchored in block 957120 (2026-07-08T03:22:41Z), 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/QZTBB2400016.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x3e92a5342ef05aa374a61d319773e7efe7223f5398f71ba57b912ff0680ae0b6. Chain 2 (Bitcoin): anchored in block 957118 (2026-07-08T03:20:19Z), 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/QZTBB2400018.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xabf3b0f5577fc67011bf09ab7ed51220705a13bfbd23a2887290f9c1ac669877. Chain 2 (Bitcoin): anchored in block 956349 (2026-07-02T11:34:59Z), 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/QZTBB2400021.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x7f7302a9478eb61aa94baceb3fca314ffaa73555ac74b434e0f1cf4fa11d08ab. Chain 2 (Bitcoin): anchored in block 960473 (2026-07-31T22:27:44Z), 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/QZTBB2400014.
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 0xc4a720a62a86ff51276c50ebe259f7e778975e14ffa076946acade2957738e95. Chain 2 (Bitcoin): anchored in block 960167 (2026-07-29T23:42:34Z), 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/QZTBB2400015.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x02d87ffc358ce923bf41aef2f8278f30a7c3bc53c2972a25c85146cf848157f4. Chain 2 (Bitcoin): anchored in block 960376 (2026-07-31T09:09:19Z), 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/QZTBB2400017.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x7dbb9fd5fc239b17409598cdb31feec946ae56bbff9ef4baac33c2ff108a3225. Chain 2 (Bitcoin): anchored in block 960468 (2026-07-31T21:25:57Z), 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/QZTBB2400019.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x8b5931463068c882ad63cefb168a03adecc2cc6c890ca8fde8568d4dc7b45458. Chain 2 (Bitcoin): anchored in block 960368 (2026-07-31T08:26:41Z), 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/QZTBB2400023.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x49ef8f9f916521a59176a76025c75960ceee33f2fc173248f7427ecc1c83ccb3. Chain 2 (Bitcoin): anchored in block 960387 (2026-07-31T10:06:30Z), 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/QZTBB2400025.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x5ca422da9799aec2a18f8744f92eabea1f85f59f496e04b32c696248116d25ca. Chain 2 (Bitcoin): anchored in block 960441 (2026-07-31T17:29:52Z), 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/QZTBB2400026.