thumb|Lunch box and vacuum bottle owned by Harry S. Truman thumb|A collection of lunch boxes for school students thumb|Insulated thermal bag with ice packs A lunch box (or lunchbox) is a hand-held co
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 0xa7842a09a55b7fde9e57998b50176f7894eb97d44dfddcbfc71685509f8c4c3d. Chain 2 (Bitcoin): anchored in block 954549 (2026-06-20T10:56:20Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/a9ff21c9-eb01-4523-a5c8-52861ae1b0c2.json and https://artists.proofprofile.net/proofs/artist/a9ff21c9-eb01-4523-a5c8-52861ae1b0c2.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 0x31dec37826faffbd5cba05a1cb25e5b2c4411801f94f905920797470663fb2bc. 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/US4TA2400051.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x922fd9143f1a667cad97c513f36ef237cbdb71cd0ac6db92e42739bcd3133900. 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/US4TA2400052.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xde4ceb14c5f17b6e7c7be306b2f5a1ed36dfdcdcfa17c2a00f22148de81ede05. 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/US4TA2400053.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xa49ad27e473beb330cc712df968042248dd81bc9cf1e61bf9619c8a269acc3a8. 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/US4TA2400054.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xbb51d6ab8d859c4940e5fb54cb4ba40a7f12ce0e55a30f2babd7efbe4061cf12. 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/US4TA2400055.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x8620084ece155a4ba03d86c0f6047513f13a706cdebef054d34b631a0f4e95c7. Chain 2 (Bitcoin): anchored in block 957145 (2026-07-08T08:56:20Z), 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/US4TA2400056.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x45ffcde7fb66f498267108cdc44c2894a92f10005b61a5f5751f23cb57dcff16. Chain 2 (Bitcoin): anchored in block 959159 (2026-07-22T17:48:40Z), 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/US4TA2400057.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x70deb0d16be91459451a5885e6cb189ed62cd4fae9fa3ea43a76df7a4310f821. 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/US4TA2400058.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xfe6bd33eaff014b6760c5c9da75f80dd7b91304cec9f7c610bb34d5a75460af8. Chain 2 (Bitcoin): anchored in block 960478 (2026-07-31T23:30:38Z), 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/US4TA2400059.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x6d386bc805e7cbdab74a3364442f3613b337566f0c045f9c424eaa5e668fb743. Chain 2 (Bitcoin): anchored in block 960381 (2026-07-31T09:50:11Z), 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/US4TA2400061.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xf4986ea593b905195e74beeb6cccab660244d3bcae0c7b1c71e2c89096c61c1d. 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/US4TA2400062.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xf368e7f3c4c59deed636ee84660a6bf07fff646b32f38c55bd31b0e58ddea947. Chain 2 (Bitcoin): anchored in block 960422 (2026-07-31T15:27:29Z), 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/US4TA2000045.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x5bb6536a8790aeb47e40bbb34c9b8aed1d3a953f63a2c0678c1afe675834322c. Chain 2 (Bitcoin): anchored in block 960294 (2026-07-30T18:46:00Z), 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/US4CB0210127.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xefe25ad76a392a44513e79e65f771bf9a5878130175cd54849ea833ea1ba5771. 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/US4CB0210128.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x57c1d7b44e4cd5ddc499018f99891e96d0b19d61501f22cafb96460c41687bd0. 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/US4CB0210131.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x4913427937a0ade678cf4a9cb55ddb42649203eb22583ec5738d8b4fbd3fa2e9. 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/US4CB0210134.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xd00a682ffec225f291ce25e7f13d094e8884ed363541ff97a6625aaf12e4bea2. Chain 2 (Bitcoin): anchored in block 960250 (2026-07-30T11:13:28Z), 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/US4CB9910013.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x06147d56ad1953cc6e17f567d8a43181ffafdbfbfaf8b122cbc3061a6074341c. 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/US4CB9910016.