Here’s the idea: you attach a QR code to your key ring that, when scanned, opens a texting window with “I found your keys!” set to send to the key owner’s phone. When I saw the instructions for this ...

As previewed last year, Google Messages is beginning to roll out QR code-based key verification to confirm that you’re “communicating with the person you intend to.” Once available, open a ...

A method known as quantum key distribution has long held the promise of communication security unattainable in conventional cryptography. An international team of scientists has now demonstrated ...