Quantum internet breakthrough could help make hacking a thing of the past

From Siddarth Koduru Joshi on Live Science.com (Sept. 3, 2020):

The advent of mass working from home has made many people more aware of the security risks of sending sensitive information via the internet. The best we can do at the moment is make it difficult to intercept and hack your messages — but we can't make it impossible.

What we need is a new type of internet: the quantum internet. In this version of the global network, data is secure, connections are private and your worries about information being intercepted are a thing of the past.

My colleagues and I have just made a breakthrough, published in Science Advances, that will make such a quantum internet possible by scaling up the concepts behind it using existing telecommunications infrastructure.

Our current way of protecting online data is to encrypt it using mathematical problems that are easy to solve if you have a digital "key" to unlock the encryption but hard to solve without it. However, hard does not mean impossible and, with enough time and computer power, today's methods of encryption can be broken.

Quantum communication, on the other hand, creates keys using individual particles of light (photons) , which — according to the principles of quantum physics — are impossible to make an exact copy of. Any attempt to copy these keys will unavoidably cause errors that can be detected. This means a hacker, no matter how clever or powerful they are or what kind of supercomputer they possess, cannot replicate a quantum key or read the message it encrypts.

This concept has already been demonstrated in satellites and over fiber-optic cables, and used to send secure messages between different countries. So why are we not already using it in everyday life? The problem is that it requires expensive, specialized technology that means it's not currently scalable.

Previous quantum communication techniques were like pairs of children's walkie talkies. You need one pair of handsets for every pair of users that want to securely communicate. So if three children want to talk to each other they will need three pairs of handsets (or six walkie talkies) and each child must have two of them. If eight children want to talk to each other they would need 56 walkie talkies. [source]