thumb|A technician referring to an instructional handbook for the operation of a machine thumb|upright|Early 20th century handbook for operating a motor car A handbook is a type of reference work, or
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 0x0e0b1f41c2da2a75827745fa2f620e56f9d9aef1f48db6fd8e8b5194c22f9690. 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/c2eacabd-4d6b-43ec-b086-24414a3d5b8b.json and https://artists.proofprofile.net/proofs/artist/c2eacabd-4d6b-43ec-b086-24414a3d5b8b.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 0x8c0309fc7ff3dfb78114db77410883ad8bdeed8a5f49a587b0bf2160b98d0bd7. Chain 2 (Bitcoin): anchored in block 959001 (2026-07-21T11:41:42Z), 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/FR2X41768488.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x4828bcc9b61f7ed8728529122d59d2a6cf4d1897dd10bdaba697dc761a669d29. 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/FR2X41867996.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x2039a5d6a2125e3638a39d7536d1b2311250035cd8d84071d9376dbb4b6b6bc4. Chain 2 (Bitcoin): anchored in block 956634 (2026-07-04T10:04:33Z), 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/DEQ021803078.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xb623370cfb6b958975fad8df90d97de37bffa44e4d1b8f7754a175b7c85c0a8c. 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/FR9Z61800215.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x1d30ec58e1f96373da4bb130855c883d9fee7639c352dc84ed65a59f92812a34. 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/FR9Z61800217.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xf1703246b553594cabf8b6aa52a6cc5996118d53b2af67d6a2aa1064b7343029. Chain 2 (Bitcoin): anchored in block 957863 (2026-07-13T14:41:15Z), 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/FR9Z61800219.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x8ca8857c57589cfe27c737e4720cb7fcbdcad512f700db3cb751157729fca7a2. Chain 2 (Bitcoin): anchored in block 958276 (2026-07-16T10:20:17Z), 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/FR9Z61900255.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x6bddf7d093332237f318ff18f8e3eceba1de384192a5e1bc6a519a68cc075fc5. Chain 2 (Bitcoin): anchored in block 958420 (2026-07-17T13:33:01Z), 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/FR9Z61900258.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x4453fc21ee744a0d6a56bde9701d78b5eb13f6742ebfda4ee41a11c4be9fee0f. Chain 2 (Bitcoin): anchored in block 956634 (2026-07-04T10:04:33Z), 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/USANG1903588.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x6dc67eea16f4c974ac05123c83cf9967c75b0da9476466308a513cd3e98c245b. 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/QZFYW2040030.
Blurred Horizons (Inspired by 'The Outlaw Ocean' a book by Ian Urbina)
Blurred Horizons (Inspired by 'The Outlaw Ocean' a Book by Ian Urbina)
Blurred Horizons (Inspired by ‘The Outlaw Ocean’ a book by Ian Urbina)
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xb995bde63c91cc99e64f3967b4013a6301cd8c25323b8f9018304d3fac822f28. Chain 2 (Bitcoin): anchored in block 960494 (2026-08-01T01:44:32Z), 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/FR9D32000015.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x74255d1392030c5745b8a2f32954b1d4181be08b6f721c3bfed217454b7b30fe. Chain 2 (Bitcoin): anchored in block 953528 (2026-06-13T15:41:10Z), 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/FR9D32000017.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x62a3764b0940f5c21583df93c7e516e1dd96b200a8899cd10d92407216edeb64. Chain 2 (Bitcoin): anchored in block 956304 (2026-07-02T03:55:08Z), 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/FR9D32000022.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x7debdfd85c0a48995ccadab6b97f3785f01e682e74b32f4f099a9df929ca41c7. Chain 2 (Bitcoin): anchored in block 956420 (2026-07-03T00:42:11Z), 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/QZHN82034434.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x35281b00d7420bf4bdc19dfe6f65ce06ed9c4cc067d78da93b8218ad57cdea10. Chain 2 (Bitcoin): anchored in block 958316 (2026-07-16T19:42:29Z), 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/GBPS83862512.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x13cc1997ccc5303873d9acc08acdecf8767f2650f91d2e46e5b283f0d7ca218b. Chain 2 (Bitcoin): anchored in block 960240 (2026-07-30T09:57:33Z), 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/DEQ022011130.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x918875b4d9faebb0e32312ace4c6ee3a03c6aef9e0f7d1ae173da06c2d5ed143. Chain 2 (Bitcoin): anchored in block 953520 (2026-06-13T13:32:09Z), 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/DEQ022011131.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xed6a523f80d39546b05ac3dea7d060ea8621a763a1df42083f64e76ae9cce611. Chain 2 (Bitcoin): anchored in block 956304 (2026-07-02T03:55:08Z), 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/DEQ022011132.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x83d941d842514c4a998337cd75af344103273ca61f40d672696ea12895cef8e4. Chain 2 (Bitcoin): anchored in block 953520 (2026-06-13T13:32:09Z), 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/DEQ022005960.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x895de049f7d8ac8fcce5cb4ff306bc9797974c35999b215f1a669bcbc6f781ee. Chain 2 (Bitcoin): anchored in block 956304 (2026-07-02T03:55:08Z), 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/DEQ022011100.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x20d41183696b8333a4a6e0fb6b5757b536a64613f587a4670689be388a2bb072. Chain 2 (Bitcoin): anchored in block 953515 (2026-06-13T12:53:06Z), 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/DEQ022011019.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xcd5ee7528ab893fa4f9c863338b1ea6ec39264146d23a50f21db79e6b31adbf2. Chain 2 (Bitcoin): anchored in block 960348 (2026-07-31T05:17:02Z), 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/DEQ022011133.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xa6e920f6137e959dda568609ceec7b837ca39d25a2d51981e8c38010b7ed657a. Chain 2 (Bitcoin): anchored in block 956634 (2026-07-04T10:04:33Z), 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/QZK6L2071649.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x98bc9b11467e5ce83586d4e8b9cb385d09382949fcc73cfc5956c989368e218a. Chain 2 (Bitcoin): anchored in block 956772 (2026-07-05T10:01:46Z), 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/FR9Z62100029.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x3b13b582103d369b4c7e2750a93f5507d6365fd4c897044e68db7e86b9309c2a. Chain 2 (Bitcoin): anchored in block 958410 (2026-07-17T12:18:07Z), 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/FR9Z62100212.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x8c216aaba4af4f3a8f36e4fa8ce0eced5f82adbae5bd4346233a869a90f0ed47. 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/GBWUL2208118.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x33e73d4f7fc7ad50ea0b2fb335fceb006e09f51cc67dcd1edc06735ce4823416. Chain 2 (Bitcoin): anchored in block 958885 (2026-07-20T13:01:04Z), 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/DEH742409720.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x26be935e7fa6734d80a5b303a02fd7d1a98cb4ba11affc0e2f241f94403aedb5. Chain 2 (Bitcoin): anchored in block 956551 (2026-07-03T21:18:05Z), 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/DEH742413695.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x5dcc21e1981adb099bd508c7d5e1aaf1c13d0d6387137ef9a1c17385a5473857. Chain 2 (Bitcoin): anchored in block 956375 (2026-07-02T16:51:38Z), 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/FR9Z62400518.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xd1e7e646661a4bbcf23b31b75892c5946986a8cdd93bae8b49184edddd08f1cd. Chain 2 (Bitcoin): anchored in block 958316 (2026-07-16T19:42:29Z), 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/FR9Z62400519.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x9885a81b04e8b286041f0abf1f3077813a47dd2e2ef857bb92dc7ec6da66459d. Chain 2 (Bitcoin): anchored in block 956634 (2026-07-04T10:04:33Z), 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/FR9Z62400522.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x6f07be1f2dc1da3b589e8a13221e287a6cdedc36dba5a389999ffce4d306137d. Chain 2 (Bitcoin): anchored in block 956711 (2026-07-04T22:48:52Z), 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/FR9Z62400523.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x3c0c3c2eb28f0a94c3b9a58644fd6d84feb06991073e97507009208dff2d342f. 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/FR9Z62100585.