Quantum secure communication models comparison

Abstract

IntroductionCommunication, in its general sense, is a sharing of information between two or more parties by any means regardless of the distance. There are two main aspects that ensure the proper communication process. They are information security that involves CIA (Confidentiality, Integrity, Availability) (Nieles, 2017) and reliability. In the following, we shall consider ourselves only with the security, in particular, the confidentiality. A solution to the confidentiality problem in communication systems is the encryption of the sharing data during its transfer, i.e., making use of cryptographic primitives in the communications.In the world of classical cryptography, one can distinguish two main classes of cryptographic primitives: symmetric and asymmetric (Stallings, 2017). Aside from their assets though, these types of primitives have substantial drawbacks, which could lead to compromising the confidentiality of communication systems. The problem of symmetric cryptography is related to not having reliable key distribution, whereas the problem of the common asymmetric cryptography is not the key distribution, but not being quantum-resistant, that is, it can be easily broken by algorithms run on quantum computers. However, there exist classical crypto methods not having such drawbacks, i.e., being assumed to be completely secure (Cheng, 2017). Although secure nowadays, the latter, for their being computational-complexity-based, could in some future instant of time be broken by discovering appropriate algorithms.Luckily, alongside the quantum computing, the field of quantum cryptography has blossomed as well. The latter could be even resistant to possible quantum attacks, that is to say, it is the only known technique at this time that provides an unconditional privacy in data transfer. As opposed to its classical counterpart, the quantum cryptography secureness is due to its utter reliance on the physical laws governing the microscopic world of fundamental particles (e.g. photons). In order to break the cryptography of this kind, one has to get over the laws of Nature, an action unlikely to be done.This kind of cryptography consists in using fundamental particles as data carriers. The information is encoded into the properties of the particles, which manifest quantum character whose fuzziness and strangeness provide uncracking masquerade of the data. In addition to that, the quantum cryptography has the advantage over its classical counterpart in that it is able to not only conceal the information transmitted over an insecure channel but also to reveal the presence of an unauthorized person, an eavesdropper, in a communication link. That is why, for the two reasons just mentioned, the quantum cryptographic primitives are regarded as probably the most powerful tool against any kind of attacks known to date.In general, there exist two main types of quantum primitives -quantum secure communication (QSC) and quantum key distribution (QKD), which are considered in Section 2. Particular attention will