Get the extension What is QR code signing?
QR code signing is a way to sign a transaction on an offline device without any data link. The unsigned transaction is shown as a QR code on the online computer, scanned by the offline device, signed there, and returned as another QR code.
Why it matters
A cable or a Bluetooth link is a channel that malware could use. A camera reading a QR code carries only the data on screen, in one direction at a time, and you see every exchange happen.
How Locker Protocol Wallet handles it
Every signature in Locker Protocol Wallet follows the same loop: the extension shows a request QR, Locker Vault reads it, decodes the transaction and shows it to you, then displays the signed QR, which the extension reads back. Large payloads travel as animated QR codes (BC-UR).
Questions
Is QR signing slower than a hardware wallet?
A few seconds more: two scans per signature. In exchange, you read the transaction on a full phone screen rather than a small device display.
Can a malicious QR code harm the offline device?
The Vault treats every QR code as data: it decodes it, shows you what it found, and signs nothing until you approve on its screen.