was a Japanese multimedia publisher which handled and oversaw video games, manga, guidebooks, and merchandise. It was founded in 1975 by Yasuhiro Fukushima as Eidansha Boshu Service Center, initially
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 0xe8e6f3c064614ad11b199670b8dc88f185eaffe440aef4d95b2d6c7dc58f2d8e. Chain 2 (Bitcoin): anchored in block 954130 (2026-06-17T19:07:14Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/7d6d345b-20a0-41fd-ad7e-cab7766f404f.json and https://artists.proofprofile.net/proofs/artist/7d6d345b-20a0-41fd-ad7e-cab7766f404f.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).