Note: the quantum no-cloning theorem, briefly mentioned in this article, deserves a much longer discussion. This will be deferred to a future publication.
In the past weeks we have talked about cryptography extensively. The basic concepts on which it is based, its strengths and weaknesses, where it currently is, and where it needs to go if it must continue to be of use to us. It must not be forgotten, though, that cryptography is a means to an end, a tool which is essential to communicate delicate messages and information. There is something else we must not forget: the communication channel.
Information can be kept secret even without cryptography, if an adequate channel is used. You are probably safe to tell your neighbor were your hidden spare key is if you whisper in their ear. However, shouting the message across the street may lead to unpleasant surprises. To keep information safe, the sender must understand the medium chosen for transmission, know whether it is a direct link to the receiver, and if other parties are able to listen in or simply interrupt the communication before the message is sent.
Many channels used for communication are inherently unsafe: it is well withing widely technical capabilities to intercept messages. That is why it became necessary to scramble messages into code, giving rise to cryptography. It is not hard to understand why. We have a strong dependence on electromagnetic waves for communication, which are inherently easy to intercept, interpret and replicate. To intercept radio communications, for example, sometimes it is enough to just erect an antennae.
Not only criminal organizations, but also governments exploit this fact. Edward Snowden, former CIA employee and US government contractor, leaked a plethora of NSA documents revealing the enormous spying operations running worldwide. These documents showed that not only the US government, but also the establishments of the UK, Canada, Australia and New Zealand, and private enterprises, were collecting civilian communications data in bulk. The excuse for this was security, however this kind of eavesdropping gives governments what many believe to be unfair advantages over the people they exist to protect.
This action is also a gross violation of privacy. It wouldn’t be worthwhile nor feasible to encrypt every single telephone communication, e-mail or file transmission. Therefore much of this information will be raw and ready for reading. Even if all the data was encrypted, it could be speculated that if anyone possessed the computing power to circumvent this protection it would be large governments and intelligence agencies.
The problem with eavesdropping stems from the fact that electromagnetic signals can be intercepted without modifying them. This is an inherent consequence of classical physics: measurements (observations, interactions, etc) do not modify the state of the system under scrutiny. It is also quite easy to simply intercept and stop a classical signal, record it and then relay it. Therefore, it is necessary to find a safer physical mechanism to exploit for communication, if not for all messages then at least for those which are the most sensitive.
Quantum mechanics presents new options for communications, as it operates very differently. The very nature of quantum states makes them susceptible to change: wave functions collapse upon measurement. If an eavesdropper attempted to intercept a quantum communication it would be noticed very quickly, as unexpected quantum states, which have already been collapsed, would arrive at the receiving end. This would allow for quick detection of an eavesdropper and termination of the communication. On the other hand, the quantum no-cloning theorem would prevent the interception and re-transmission of signals, as it prohibits the replication of quantum states if they are previously unknown. Due to wave function collapse, whatever the eavesdropper reads would not be the full state which was sent, and they would not be able to recreate it .
Once again, quantum mechanics has come to the rescue of the worlds of communication and cryptography. Mastering the properties of the quantum world seems to be one of the most viable options to ensure the future of privacy and Internet security. Be it to make the current infrastructure safer against classical threats, or to ensure data security from quantum computing, a way forward is quantum mechanics-based technology and algorithms.
Stay tuned to find out how Quantum1Net’s network will take on the eavesdropper problem and more.
Quantum1Net is developing the means to keep the digital world quantum-safe for years to come. Founded in 2017, Quantum1Net combines decades of industry experience with cutting edge technology to create quantum-secure encryption services. Starting with making Bitcoin safe from quantum hacking, Quantum1Net will roll out a wide range of novel products to protect digital transactions and communications from quantum hackers.