G-MAC or G-Mac may refer to: G-MAC: Great Midwest Athletic Conference, United States G-Mac: Graham McDowell, golfer
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 0xb7d9b5d0bc918f33ac2523501618aa8b337bcc7f43599c9f6b5188258d2aba5a. Chain 2 (Bitcoin): anchored in block 954065 (2026-06-17T08:10:43Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/50d944f9-61bc-488b-af73-7e286b0ed382.json and https://artists.proofprofile.net/proofs/artist/50d944f9-61bc-488b-af73-7e286b0ed382.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).