right|225px|thumb|"The Difficult Lesson" by William-Adolphe Bouguereau (1884) right|225px|thumb|Falconry lesson A lesson or class is a structured period of time where learning is intended to occur.
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 0xad32587d8324f390d6d9efb21e9e377ad79e07f167577ce2e2980d68bbb3508c. Chain 2 (Bitcoin): anchored in block 954615 (2026-06-20T22:44:50Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/c59062c4-1f36-4b4a-9ad2-60313db0b602.json and https://artists.proofprofile.net/proofs/artist/c59062c4-1f36-4b4a-9ad2-60313db0b602.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 0xec84945a1cd52ac095b34adcad579c93a067773a8b2f624a734aded7e2cd27c8. 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/SE6XW2550425.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x0ac1db8e9a3554d4304da6984e11007e149587fe3a571ae811d26e4a36a37a3e. 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/SE6I32500494.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x51f4c774aee009f8ba4b7ae8d64953c12269235e86e276f17451f5ee4fdd2251. 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/SE6SA2599934.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x6c599ec7e3fe4720791500d4d36baba78712aeeabd2a775f8867248a7019f08c. Chain 2 (Bitcoin): anchored in block 958194 (2026-07-15T20:32:27Z), 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/SE6I32500599.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xf7fea17964a903bbc59c8fbfae5413a00b0377638ffe534741ec151b5c13f082. Chain 2 (Bitcoin): anchored in block 958822 (2026-07-20T04:30:07Z), 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/SE6I32573111.