Keycard Blog

An air-gapped hardware wallet is a signing device that has no wired or wireless data connection to the internet, ever. Instead of USB cables or Bluetooth, it exchanges transaction data through QR codes, scanned by a built-in camera and displayed on its own screen. This physical separation between the signer and any networked computer is the "air gap," and it exists to prevent remote attackers from ever reaching the private keys. How an Air Gap Actually Works at the Hardware Level Most hardwar