Classical communications, such as those over email or phone, are vulnerable to eavesdroppers as today’s data encryption is based on the factorization of large integers, which is an easily solvable operation on a quantum computer. Considering the fact that large quantum computers are only five years away from commercial exploitability (according to Google), this is a dangerous situation to be in.
The good news is, there is a solution, and it lies in quantum key distribution (QKD).
QKD uses particles to allow two remote parties to produce a shared random secret key, which is known only to those two parties. This secret key enables the encryption and decryption of messages, and it is super-safe thanks to the principle that it’s based on – the uncertainty principle. Based on this concept, secure quantum networks are being built on a large scale in many countries (with China leading the way), so it’s important to understand the ultimate limits of QKD.
Now, in an article published in Nature Communications, scientists explain they have managed to establish the boundaries of quantum secure communications through the most important communication lines, including optical fibres.
Professor Stefano Pirandola of the University’s Department of Computer Science explained that this is a breakthrough development as it establishes the ultimate performance that none of the point-to-point protocol of QKD can surpass.
Source:
Phys.org (https://phys.org/news/2017-04-boundaries-quantum.html)
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