thumb|An Egyptian boomerang; National Archaeological Museum, Athens, Greece. thumb|Australian Aboriginal boomerangs A boomerang () is a thrown tool typically constructed with airfoil sections and desi
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 0x7780aa17ab15c4d3b32f3e386c4e295a5bead2b5a22b10cd5b41c343a57b0a9b. Chain 2 (Bitcoin): anchored in block 953407 (2026-06-12T19:24:56Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/d84b446b-a5d4-4e7a-bfaa-c5a21b88c70d.json and https://artists.proofprofile.net/proofs/artist/d84b446b-a5d4-4e7a-bfaa-c5a21b88c70d.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).
Boomerang (Expanded Edition) (feat. Mark Stein)
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 0x0790574362889c33249d75ad2d273f16b1aca690957e8bd3073c1a0ee25938e3. Chain 2 (Bitcoin): anchored in block 958728 (2026-07-19T12:24:55Z), 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/IDAC52003060.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x2a52b1f30614353a9d7518f835afcf87c8b8c7c2aaff8fd6a87aaa44b9b1ded8. Chain 2 (Bitcoin): anchored in block 958392 (2026-07-17T09:46:31Z), 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/IDAC52003061.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x10651a975c9274465d22d8c03a5d052f02e13d0b34f1169fa790300a2a93ccbd. 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/IDAC52003062.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x6c659401eff938389a6996c50cf3c09f4ae4cb48f5119de18d7a4ec3392257f8. 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/IDAC52003063.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x278e3a182c07be557f1eca81f5ac535e34b744e93dbf35e2153997556b04e0ca. Chain 2 (Bitcoin): anchored in block 958600 (2026-07-18T19:24:05Z), 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/IDAC52003065.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x6ec3fb7a14a9c51dc3fb5151676246e590b7416bead7e336417f6d053d780e94. Chain 2 (Bitcoin): anchored in block 958714 (2026-07-19T09:51:44Z), 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/IDAC52003066.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x499015c40ec5b33f3742140052da985b53094854b5bee39ccd1bb28f0375c26b. Chain 2 (Bitcoin): anchored in block 958607 (2026-07-18T21:01:11Z), 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/IDAC52003067.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xfc343415fa92ac21e1633e0b3378e34f68d9d3dc2d7041c57a28733df54369e5. Chain 2 (Bitcoin): anchored in block 958714 (2026-07-19T09:51:44Z), 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/IDAC52003069.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x805f78e7a5ad144e82aeb7c6b94a847eded4ad930d42cceea06f8f6b0462cf66. Chain 2 (Bitcoin): anchored in block 958256 (2026-07-16T07:22:18Z), 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/IDAC52004162.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x9ed1d7e991fa6ead9ec50f983b125ce099d13a8e6d983f455645c151202b386b. Chain 2 (Bitcoin): anchored in block 959087 (2026-07-22T02:05:55Z), 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/IDAC52004165.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x44cf3e5787d8116cc0e46470b95ea6960e86a48d12e04a2d22b419ccad106638. Chain 2 (Bitcoin): anchored in block 959043 (2026-07-21T18:40:26Z), 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/IDAC52004167.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x3f5f62dabcb6269a8a99fc9ae28cf4a8de3bd8b66401d07e774249f0b5943001. Chain 2 (Bitcoin): anchored in block 956725 (2026-07-05T01:12:41Z), 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/IDAC52004169.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x9a090dd4f2269b734f7d74c2e15c5a53465364f91af5a974b4445c8d584727aa. Chain 2 (Bitcoin): anchored in block 957741 (2026-07-12T18:30:59Z), 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/IDAC52004171.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xfc5b082387daf4dceccc5cfef7a21008b864831a1f2b3d3676785d81cb31af7a. Chain 2 (Bitcoin): anchored in block 958812 (2026-07-20T03:24:09Z), 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/IDAC52004172.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xca759ff499b8fcf049d116008f6ff33336f15911f969eeeeb99bcd07c8e7e7c8. Chain 2 (Bitcoin): anchored in block 959063 (2026-07-21T21:45:32Z), 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/IDAC52004173.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x7b88bc6253b2b87cd3d503758125b27267aff157f8be8a96b461f2c8264689d0. 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/IDAC52004175.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x503018bac62226f71b4b457ff88a4add2107f88560cb2c7b11134b611249c37b. Chain 2 (Bitcoin): anchored in block 959051 (2026-07-21T19:48:03Z), 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/FR6V82418485.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x28e96ed0a373944fc793406d10432b3b59593da0dda4e16eada5332fb38f5ce6. Chain 2 (Bitcoin): anchored in block 958913 (2026-07-20T16:58:47Z), 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/FR6V82418486.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xa617dcef4a34267fce1152bf1cc7e81e321d7170f683aeecbbf312fb22148007. Chain 2 (Bitcoin): anchored in block 958480 (2026-07-18T02:58:58Z), 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/FR6V82418487.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xc4ed858b94d3f0c4754f772364d484ef4993dfc81dc9610574c7ee141bbb23ca. Chain 2 (Bitcoin): anchored in block 959008 (2026-07-21T13:14:05Z), 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/FR6V82418488.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xd4005fc9154d07e2cf74454911b2aa8aabd2148c9e4702cb9e48577fcefd2b3b. Chain 2 (Bitcoin): anchored in block 959087 (2026-07-22T02:05:55Z), 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/FR6V82418489.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xa568cc9bad18b4d18740538b7791c7ab0ac064dcccc417f2150f280474ff039e. Chain 2 (Bitcoin): anchored in block 958955 (2026-07-21T03:03:40Z), 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/FR6V82418492.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x6560ad91bdc9e284ecb60b2dce8dc484f543098f9c7fc0d42558130e44021eb6. Chain 2 (Bitcoin): anchored in block 959058 (2026-07-21T21:09:36Z), 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/FR6V82547941.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x595f4edab8ad5710c591331d79a682fc3dbc1fbadb675996d1c1ebf7b4ca016a. Chain 2 (Bitcoin): anchored in block 956856 (2026-07-06T01:25:57Z), 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/FR6V82547944.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xb1eaee240d6d82137a5f889e098267597644dcfdac10879b8625af85633bf912. Chain 2 (Bitcoin): anchored in block 958211 (2026-07-15T23:24:33Z), 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/FR6V82547950.