Chad Lefkowitz-Brown (known as Chad LB) (born September 8, 1989) is a New York-based saxophonist and recording artist recognized for his work as a soloist in the genres of jazz and pop music. He was a
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 0xd49d38652be6948640ea798bc9fb009a6da629f522e205feb4763b6c817708d1. Chain 2 (Bitcoin): anchored in block 953423 (2026-06-12T21:20:00Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/fa8ab6b8-e91f-4e3d-94f3-0dbbd4df498e.json and https://artists.proofprofile.net/proofs/artist/fa8ab6b8-e91f-4e3d-94f3-0dbbd4df498e.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 0xffe5e01d438a6546425bec4aa5f88e771e5b9edaba4d4b5b904f7fb177f30053. Chain 2 (Bitcoin): anchored in block 957888 (2026-07-13T17:43:59Z), 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/QMBZ92024108.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xd71c2eb5aac8b9e798cb7532afe46d28edd2d618465af19c7ab96a2838fbfbaa. Chain 2 (Bitcoin): anchored in block 958444 (2026-07-17T19:12:23Z), 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/QMBZ92024109.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xdfa99907704705cf9fee3c89e4b125a062b80ba821da69db61506d41f4382b00. Chain 2 (Bitcoin): anchored in block 958544 (2026-07-18T12:14:37Z), 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/QMBZ92024110.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x1a9a1a4da93212554c50ac56c65d83c787592f30294eb1e4124d4c7e755e8179. Chain 2 (Bitcoin): anchored in block 956776 (2026-07-05T10:59:37Z), 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/QMBZ92024115.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x0f0442e5dab179d082a56c35089a7b105186f11217525f2cbf3573720289e076. Chain 2 (Bitcoin): anchored in block 956857 (2026-07-06T01:26:17Z), 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/QMBZ92024116.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x0c7ded78185ddc08b5b015016470c1116bb007bb951c6165ac773c5c7ab18ec6. Chain 2 (Bitcoin): anchored in block 958842 (2026-07-20T09:45:52Z), 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/QMBZ92024117.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x4aec1c3270e071e376d027b9854f3096f2f7a2109c0129f996083fb03d0453a7. 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/QMBZ92190733.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x4109692c5a2c13471bb39567493af652936b74b9ef8618207bddb68348aae7af. Chain 2 (Bitcoin): anchored in block 958690 (2026-07-19T07:14:39Z), 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/QMBZ92190734.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x9b571cafe442baba49a51ae77194a25456e9bc123a6729451c9bd6accac4f6ce. Chain 2 (Bitcoin): anchored in block 958461 (2026-07-17T23:18:11Z), 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/QMDA72417929.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x6b9d58345856594fb5f4acdb83e27eb6b33242dcf25ffa9c068cfb611bf42e60. Chain 2 (Bitcoin): anchored in block 956776 (2026-07-05T10:59:37Z), 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/QMDA72417930.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xf980609625c9898c66439f1898868d8beeae6eca7153ef0f291aecde5c96e8af. Chain 2 (Bitcoin): anchored in block 958124 (2026-07-15T11:02:15Z), 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/QMDA72417932.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x6b9d58345856594fb5f4acdb83e27eb6b33242dcf25ffa9c068cfb611bf42e60. Chain 2 (Bitcoin): anchored in block 956545 (2026-07-03T19:59:51Z), 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/QMDA72417930.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x2ddefc10db2d5d009ceedabb8be58a41170459a4d058bbabdfe9807ad8d10346. Chain 2 (Bitcoin): anchored in block 958286 (2026-07-16T12:43:37Z), 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/QMDA72417931.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xf980609625c9898c66439f1898868d8beeae6eca7153ef0f291aecde5c96e8af. Chain 2 (Bitcoin): anchored in block 958377 (2026-07-17T06:48:00Z), 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/QMDA72417932.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x607fd62023469a399d687831a79f1823d2bcaebbe484bde57008d25ec67c9d1a. Chain 2 (Bitcoin): anchored in block 956474 (2026-07-03T08:56:35Z), 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/QMDA72417934.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xe942047d6d06ff8bb777ddb04849e76a25991c0ed28f6a13999d2b01e3c0a9b5. Chain 2 (Bitcoin): anchored in block 957770 (2026-07-12T23:17:00Z), 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/QMDA72417935.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xf866d4d3d7f5111c99616b76f98978fce32681f8bb97783e6088395678276d7b. Chain 2 (Bitcoin): anchored in block 959010 (2026-07-21T15:49:47Z), 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/QMDA72417936.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xff4c2faf2fcb4ea66f1212c965d3a2a27736d5ea8a68a7ffc351b5affd41eebc. Chain 2 (Bitcoin): anchored in block 958180 (2026-07-15T17:59:52Z), 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/QM6P42521253.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xdd0e56e77e62239ef5ba1fe1bcd5d2723226ac1cde9ef4fb0db224525e4ba887. Chain 2 (Bitcoin): anchored in block 957776 (2026-07-13T00:05:10Z), 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/QM6P42521258.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x497fa1a339178847f980afcca39d1f02d65b375224274716b51e8c7727233fd6. Chain 2 (Bitcoin): anchored in block 959137 (2026-07-22T15:39:43Z), 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/QM6P42521257.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x39ce991b39d95c92dd80bc087195b8a6e204f18484177a5f290e0ce47473f520. Chain 2 (Bitcoin): anchored in block 956889 (2026-07-06T06:56:49Z), 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/QM4TW2312108.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xe196b5dc52f9ef80782c160eec28d97bdaa000be1fc1aff181f2874d7cc810ee. Chain 2 (Bitcoin): anchored in block 960302 (2026-07-30T20:09:33Z), 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/QM6N22143960.
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