Brunnian links are a type of nontrivial link – or knot – where multiple linked loops become unlinked if a single loop is cut or removed. Beyond ‘fun’ disentanglement toys and a tantalizing subject of ...

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.

Allowing people into your home or property when you’re not there used to be either leaving a key under a doormat, or a complicated business of sending a set of keys by courier or asking a neighbour to ...

Passkeys offer a way of confirming you are who you say you are without remembering a long, complicated password, and in a manner that's resistant to common attacks on passwords like phishing and ...