Terra preta (, literally "black earth" in Portuguese), also known as Amazonian dark earth or Indian black earth, is a type of very dark, fertile anthropogenic soil (anthrosol) found in the Amazon Basi
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 0xc8334d6587e388e82d013bdff5c5b727340698dfe8886192bdacc34104f3bbda. 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/4c1d91bf-537d-479a-b6ce-2f5b97edca7d.json and https://artists.proofprofile.net/proofs/artist/4c1d91bf-537d-479a-b6ce-2f5b97edca7d.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 0xc55433f41b796424858aa920f02f4fb49bce6c056c467976682f1ee20b7a9387. Chain 2 (Bitcoin): anchored in block 958121 (2026-07-15T08:02:12Z), 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/US7VG1475980.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x96e1383e16f7c774fcfbb2e4549f1f0c100ad0fbf4fbe994157c5f8be45e5605. Chain 2 (Bitcoin): anchored in block 956826 (2026-07-05T19:27:56Z), 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/BCDPN2200014.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x820b551e841f6eb799267a5c8e0d611ae871e9a10c787709e8ea4906a039566b. 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/BR4IW1300005.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x23f70b4f4d0c94aebff77f0908df75343cf824367d9222f6d984ac38ac8f25f7. Chain 2 (Bitcoin): anchored in block 956302 (2026-07-02T03:30:09Z), 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/BRAPI1600035.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x92cb10691f6750990133645112c64e9499dca3a9e2d87fbf542495629afb596b. 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/BX8TS2000002.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x359699d6d2104d305ccfda47fbbd8a45a1b8f8ea7591ce92306a042166783b6e. Chain 2 (Bitcoin): anchored in block 953513 (2026-06-13T12:47:07Z), 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/BR4IW2100013.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xee0602393f5d36087bd4fe839db5d14d7046d53d98181c276467515a50f33efc. 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/BR4IW2300002.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xb5f3a942607e96828b0e2d1823bcd286cc5cc620f7bc8146c3cd8b56bc1d0046. 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/US7VG1677157.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x112ad0e3f66572d23756d0978d0bb1722767c97840017ba59f7d63fa5ca91bfb. 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/BR33B1300001.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x0a3a59c84ffa4a93afe8c2dc77ef7115e9f83aed96420b93243112c086ad5a8d. Chain 2 (Bitcoin): anchored in block 960410 (2026-07-31T13:50:38Z), 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/BXA6P1700007.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x68d3762462ca7054be0108c82f7884dabd61e761207d40aff595b1f1b1947587. Chain 2 (Bitcoin): anchored in block 956302 (2026-07-02T03:30:09Z), 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/BRDA01300006.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xd96bf4d5099c94d78374929066743350998fa7bbd30be31990a4fb3bdf68dbb8. 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/DGA0P2453621.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x29f60d895500c644a814e59eb1510226411dd8896baf1eaf4c61383509134cb8. Chain 2 (Bitcoin): anchored in block 960334 (2026-07-31T02:19:15Z), 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/BR46Z1400005.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x3f1f22478069354b0494c464bcf85fe8e5da958e4ee3e590192e1fedabda0542. 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/BR7I21200001.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x7f4cf37a28041ec02f5b80ab005174e21d61c373c624f3f4daebf74d15a31f9a. Chain 2 (Bitcoin): anchored in block 956302 (2026-07-02T03:30:09Z), 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/BR7I21200011.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x685763e7b4233c721028bc4e416b61a1a0ddceae3fe5973b89171f4254ac3edd. Chain 2 (Bitcoin): anchored in block 960268 (2026-07-30T14:53:07Z), 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/PTNS11600002.