For thousands of years, if you wanted to send a secret message, there was basically one way to do it. You’d scramble the message using a special rule, known only to you and your intended audience.

The security system that underlies the internet makes use of a curious fact: You can broadcast part of your encryption to make your information much more secure. When you purchase through links on our ...

Almost everyone has experienced fumbling for keys in the dark, misplacing a set right before leaving the house, or worrying about who might have a copy. Traditional keys come with real drawbacks. They ...