Julia Kagan is a financial/consumer journalist and former senior editor, personal finance, of Investopedia. A message authentication code (MAC), or tag, is a security code that is typed in by the user ...

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 ...

After previewing last year and sharing more details in May, Key Verifier is “now available to all Android 10+ users” to protect against impersonators and fraudsters. This system uses QR codes to ...

How certain are you that the person you’re messaging is who they say they are? You might have saved the contact of a friend, family member, or co-worker on your phone. Their name pops up in a message, ...

Apple has a little-known security feature, often described as a hidden 'secret code,' that can reveal if someone is snooping on your private conversations. Every iMessage chat generates a unique ...

You could do worse than to confuse the meanings of "code" and "cipher"—even cryptographers sometime use the terms as though they had the same meaning. There is, however, a definite distinction between ...