is a Vocaloid by Internet Co., Ltd. Her voice is sampled by Megumi Nakajima. The mascot of the software is called (stylized as GUMI). She is also sometimes called Megpoid GUMI, or GUMI Megpoid. The
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 0xb807e9b56ad784ea2b5d5725c429e9e60d9e5428fad1153b4ca9ac60f360cbee. Chain 2 (Bitcoin): anchored in block 953970 (2026-06-16T16:09:39Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/29c5e514-2a5f-4c83-a1de-4c1595222371.json and https://artists.proofprofile.net/proofs/artist/29c5e514-2a5f-4c83-a1de-4c1595222371.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).