9 Communication and security
The security of communications is extremely important. The effectiveness of encrypting a message will determine whether anyone unauthorised can read it. Similarly, decrypting a message can give the advantage to an eavesdropper. The film The Imitation Game (2014), starring Benedict Cumberbatch as Alan Turing, provides a good background to the decrypting or ‘cracking’ of the German Enigma machine during the Second World War (Figure 8).
The outcome of this cutting-edge research was the first electromechanical computer (called a Bombe), developed by Gordon Welchman, and the electronic Colossus, developed by Tommy Flowers.
Governments around the world have vested interests in maintaining communications security of their own systems as well as cracking the codes of other countries’ systems.
As light can be viewed as a wave or a particle (see Section 3), quanta of light called photons are used for secure communications. How relevant is this to the ISS? Well, in 2012, NBC News published an article (Hsu, 2012) on the subject of quantum key distribution. In it discusses a potential quantum entanglement for space experiments (QUEST) experiment to test quantum communication to and from the ISS. If you have some spare time this week, give this optionala read.
What other types of quantum technology are under investigation? Figure 9 lists the possible space applications of quantum devices from quantum key distribution (QKD) to quantum communication complexity (QCC). It also summarises the quantum research introduced in Video 5.
Next you will complete the end-of-week quiz.