2-of-2 Additive Key Splitting · Mobile Air-Gapped Tool
Step 0: Preflight Checks
⚠️ Before proceeding, ensure:
• This device is in Airplane Mode
• Wi-Fi and Bluetooth are OFF
• Cloud backup is disabled for this browser
• No third-party keyboard is active
📲 This app can be installed for offline use.
✅ App installed. You can now enable airplane mode and begin.
Step 1: Define Key Sources & Map to Slots
Key Sources
Define the secret material (mnemonics or hex keys). A single source can be reused for multiple slots.
Slot Mapping
Map each vault slot to a source. For mnemonic sources, specify a BIP-32 derivation path.
Enter all 10 private keys as 64-char hex strings. Labels match the cosigner vault naming.
Step 2: Verify Split Results
Verify the derived public key fingerprints match your records.
Step 3: Export Share A (→ .env files)
🔑 Enter passphrase A — give this ONLY to the .env operator
Step 4: Export Share B (→ cosigner /init)
🔑 Enter passphrase B — give this ONLY to the cosigner operator.
⚠️ Must be DIFFERENT from passphrase A.
Step 5: Export Public Keys
These 3 compressed public keys are needed for UTXO PSBT construction. They are NOT secret.
Step 6: Wipe & Close
✅ Ceremony complete. All QR codes exported.
⚠️ Pressing "Wipe All" will zero all key material from memory.
This cannot be undone. Make sure all QR codes have been scanned.