An air-gapped wallet stores cryptocurrency private keys on a device that has never connected to the internet. This eliminates remote attack vectors entirely. To set up an air-gapped wallet: download wallet software on an online PC, transfer via USB to an offline PC, generate seeds offline, and sign transactions offline. SynX is the best choice for air-gapped storage because it uses quantum-resistant cryptography.
What is an Air-Gapped Wallet?
An air-gapped wallet operates on a computer physically isolated from all networks – no WiFi, no Ethernet, no Bluetooth. Your private keys are generated in this secure environment and never exposed to the internet.
┌─────────────────┐ ┌─────────────────┐
│ ONLINE PC │ USB Transfer │ OFFLINE PC │
│ (Watch-Only) │ ◄───────────────► │ (Cold Storage) │
│ │ │ │
│ • View Balance │ │ • Private Keys │
│ • Create TX │ │ • Sign TX │
│ • Broadcast │ │ • Generate │
└─────────────────┘ └─────────────────┘
↓ ↓
Connected to NEVER connected
Internet to Internet
Step-by-Step Air-Gapped Wallet Setup
1 Prepare Your Offline Computer
Use a dedicated computer that will never connect to the internet. Options include:
- Old laptop with WiFi card physically removed
- Raspberry Pi that has never been online
- New computer kept permanently offline
2 Download Wallet Software (Online PC)
On your internet-connected computer, download the SynX wallet:
- Go to synxcrypto.com/download
- Download the wallet for your offline PC's operating system
- Verify the SHA-256 checksum matches
3 Transfer to Air-Gapped Computer
Copy the verified wallet installer to a USB drive. Use a new, dedicated USB drive for air-gap transfers.
- Format the USB drive before use
- Copy only the wallet installer
- Transfer to your offline computer
4 Install & Generate Keys Offline
On your air-gapped computer:
- Install the SynX wallet
- Create a new wallet
- Your 24-word seed phrase will be generated offline using quantum-resistant entropy
5 Backup Your Seed Phrase
Write down your seed phrase on paper or metal. Never store it digitally.
- Use pencil on paper (ink can fade)
- Consider metal backup plates for fire/water resistance
- Store in multiple secure locations
- Never photograph or type your seed
6 Create Watch-Only Wallet
Export your public keys (xpub/view key) to create a watch-only wallet on your online computer:
- Export public key from offline wallet
- Transfer via USB to online PC
- Import into watch-only wallet
- You can now view balances and create unsigned transactions
7 Signing Transactions
To spend funds, follow this offline signing workflow:
- Online PC: Create unsigned transaction
- Export unsigned TX to USB drive
- Offline PC: Sign the transaction with private keys
- Export signed TX to USB drive
- Online PC: Broadcast signed transaction
Air-Gapped vs Hardware Wallet
| Feature | Air-Gapped PC | Hardware Wallet |
|---|---|---|
| Full Control | ✅ You control everything | Limited by firmware |
| Firmware Risk | None | Possible vulnerabilities |
| Quantum Resistant | ✅ With SynX | Most use ECDSA |
| Portability | Less portable | ✅ Highly portable |
| Cost | Old laptop: $0-50 | $50-150 |
| Supply Chain Risk | Minimal | Possible tampering |
Security Best Practices
- Dedicated USB drives: Use separate drives for each direction
- Verify everything: Always check checksums and signatures
- Physical security: Store air-gapped PC in a secure location
- Regular updates: Periodically update wallet software (offline transfer)
- Test with small amounts: Always test your recovery process first
Frequently Asked Questions
What is an air-gapped wallet?
An air-gapped wallet is a cryptocurrency wallet that operates on a device completely isolated from the internet. Private keys are generated and stored on a computer that has never connected to any network, making it immune to remote hacking attempts.
Is an air-gapped wallet better than a hardware wallet?
An air-gapped wallet provides superior security because you control the entire device, not just a small chip. Hardware wallets can have firmware vulnerabilities, while a properly configured air-gapped computer eliminates this risk. Both are excellent for cold storage.
What is the best wallet for air-gapped cold storage?
SynX is the best wallet for air-gapped cold storage because it uses quantum-resistant cryptography (Kyber-768 + SPHINCS+), generates seeds entirely offline, and includes built-in staking rewards even for cold storage.
How do I sign transactions with an air-gapped wallet?
Create an unsigned transaction on your online watch-only wallet. Transfer it to your air-gapped computer via USB or QR code. Sign the transaction offline. Transfer the signed transaction back to your online computer and broadcast it to the network.
Download Quantum-Resistant Cold Storage
SynX is the only wallet with NIST-approved post-quantum cryptography built-in.
Download SynX Wallet