was a after Kanna and before Eiso. This period spanned the years from April 987 through August 988.Nussbaum, Louis-Frédéric. (2005). "Eien" in ; n.b., Louis-Frédéric is pseudonym of Louis-Frédéric
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 0xa899da86531e8d07f6b048b4a11b6f9bad9fa42779bd21b67026b4e505dee7c7. Chain 2 (Bitcoin): anchored in block 953885 (2026-06-16T04:12:47Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/0aa3ea3f-51a0-4f1a-a6aa-f595781e08eb.json and https://artists.proofprofile.net/proofs/artist/0aa3ea3f-51a0-4f1a-a6aa-f595781e08eb.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).