A decade ago, it was the mass deployment of CCTV cameras across public spaces across the world. Now, it's facial recognition surveillance. Test yourself on how much you know about this technology and its threats to your freedoms and rights.
Encryption is a very old technique. It just refers to the process by which we can hide the meaning of something by using a code. We explain how it helps protect our privacy and our money, and how authorities are using hacking to get round it.