Quantus Cold Wallet

Quantus Labs

About this app

Quantus Cold Wallet turns a spare phone into an offline hardware wallet.

Download the app, then put the phone in airplane mode. Your keys are created on this device and never leave it. To send, scan the transaction from Quantus on your other phone, check the details, and show the signature back as a QR code. No cables. No Bluetooth. No network.

• Air-gapped signing over QR codes
• No blind signing: every transaction is shown in plain text before you approve
• Post-quantum keys: ML-DSA (NIST FIPS 204), no elliptic curves
• A checkphrase for every account, so you know you’re pairing the right key
• Unlock with device authentication
• Create a new key or import an existing recovery phrase

Works with the Quantus app on your other phone. Also compatible with Quantus CLI.

Quantus Cold Wallet is self-custodial. It signs transactions locally; the connected device broadcasts them. Keep your signing device and recovery phrase secure. Losing both may permanently prevent access to your funds.

What’s new

Quantus Cold Wallet
Use an offline phone for secure signing