Earlier this year China held the world's first totally hack-proof video conference. That's a big claim to make but scientists are standing by it. Security was underwritten by the laws of physics.
Among the 5,500 or so satellites circling the Earth there is one called Micius, or Tiangong2. It was launched from the Gobi desert in 2016 as part a Chinese mission called QUESS. Without wandering off into the wild beyonds of entangled photons, which I only pretend to understand, let's just say that if you try to hack a message from Micius, then it will not be sent. If that sounds like inverting cause and effect it's simply because our language wasn't made for this stuff. Let's try metaphor.
Imagine you want to steal the Mona Lisa. While casing the joint you discover that the only way in is by way of a particular door with a very special key. That's because if you try to get in any other way, the Mona Lisa will not be hung on the wall. You can sort of imagine that, I hope? Being a canny burglar, you adjust your plan. You will now steal the key first. The trouble is, if you steal the key then the lock will be changed. It's no use wearing a disguise... the mere fact that the intended person does not have the key (whether they know it or not) means that it will no longer work. And it's no use bashing a hole in the door; if you do that you'll automatically find you've entered the wrong building.
That probably didn't help! Never mind, the point is that very soon we will be relying on systems that simultaneously offer us everything and nothing in terms of security. Quantum computers are set to render our passwords obsolete. FaceBook and Google are sharing our movements and preferences. Communication can be monitored to whatever extent it suits those who have access to the tools. And HTTPS is riddled with holes, thanks to the public key infrastructure. Besides, if all else fails there's a very nasty technology called van Eck phreaking.
There's a delightful illustration of this modern security paradox. You can access the world's most secure video conference from pretty much anywhere in the world, without a login or password, using any standard Internet-connected device. It's available on YouTube.
It's as if you'd given up all hope of breaking into the Louvre only to get home and find Mona taking selfies in the lounge.