Sijo (, ) is a Korean traditional poetic form that emerged during the Goryeo dynasty, flourished during the Joseon dynasty, and is still written today. Bucolic, metaphysical, and cosmological themes a
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 0x7c978adfa4bbc614cf9484e3b66c0ccea1fb962062ffb631ac6cdf0a587f1eab. Chain 2 (Bitcoin): anchored in block 953972 (2026-06-16T16:31:10Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/2a8c56b2-53c8-4c2c-a699-7e869e947e19.json and https://artists.proofprofile.net/proofs/artist/2a8c56b2-53c8-4c2c-a699-7e869e947e19.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 0x85c554987f1bd7dd79f1bafcacbb84d0e34f998712f6417c22ea3b4d74cc80c6. 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/SE6O22000401.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x0b58c56903db1e7def43b36780cdc4e46634ee1f7dbbb8de4b8e966c36defe44. 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/SE6022000101.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x5c4e88ce8a61c3b4ec6711dcea134ae553cdbf5b6f3b7ac4ab7230a92c3f2335. 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/SE6022000102.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xb80577cbff54ca14f135f303f40781dc7eb4016a8075366e63db83790a5dc3e5. Chain 2 (Bitcoin): anchored in block 960276 (2026-07-30T16:01:17Z), 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/SE6022000104.