thumb|Class Symbol thumb|TOPCAT K1 with 18 ft LOA thumb|TOPCAT K2 with 17 ft LOA thumb|TOPCAT K3 with 16,1 ft LOA The Topcat is a one-design sailing catamaran boat class which is divided into several
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 0x8762434cc119f1feab4207464072099f2f8da6f9b5d42b78c9b6d61a3ea7a0f1. Chain 2 (Bitcoin): anchored in block 953741 (2026-06-15T04:44:49Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/9ff2a6f2-93cb-4546-9a2a-63750751e8ef.json and https://artists.proofprofile.net/proofs/artist/9ff2a6f2-93cb-4546-9a2a-63750751e8ef.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 0xb677f0198787aae874cfd48b2b5146df4ec67117baa251bd68ffba53ec6ccb82. Chain 2 (Bitcoin): anchored in block 958861 (2026-07-20T10:02:52Z), 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/USL4Q0782369.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x2f52d9480de8fb1b7f6020cc08cdce9365f9868ae357fc7d3c50d49034257e2a. Chain 2 (Bitcoin): anchored in block 958362 (2026-07-17T04:32:48Z), 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/USHM21006388.
Life Lit (feat. Choppa City Boy Snipe & Utp Skip)
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x2e59708b10ba740a63629859c42081426e6d6a4d58697a21f1fc61d3b387b99d. 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/QMKKH2201081.