April Underwood is an American venture capitalist and board director who was the chief product officer at Slack. She founded Adverb Ventures in 2023 with Jessica Verrilli. Before joining Slack, she h
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 0x15c5b51b50020ed06571b8ecdcb04df53a66598c9128c8db3a547e5144c2dc13. Chain 2 (Bitcoin): anchored in block 954066 (2026-06-17T08:11:48Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/69af27f1-0b8a-4384-8fb5-c95869cae3bd.json and https://artists.proofprofile.net/proofs/artist/69af27f1-0b8a-4384-8fb5-c95869cae3bd.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).