Quantum cryptography: Opportunities and challenges

Abstract

Quantum information processing is a new and dynamic research field at the crossroads of quantum physics and computer science. Once a quantum computer becomes reality, it will possess massive parallel processing capabilities. Although this goal is still quite distant, certain limited applications have been developed. One of them is quantum cryptography, exploiting Heisenberg’s uncertainty principle to allow two remote parties to exchange a cryptographic key without a possibility for a third party to intercept the key during its exchange between the sender and the recipient. Current popular exchange of keys using public key cryptography suffers from two major flaws. First, it is vulnerable to technological progress. The development of the first quantum computer will consequently make the exchange of a key with public key algorithms insecure. The second flaw is the fact that public key cryptography is vulnerable to progress in mathematics. These threats simply mean that public key cryptography cannot guarantee future-proof key distribution. Quantum cryptography solves the key distribution problem by allowing the exchange of a cryptographic key between two remote parties with absolute security, guaranteed by the laws of physics. Mechanics of this exchange has been described in the paper. The quantum cryptography system is very promising and advancements are being made to improve upon the technology, most notably a wireless implementation, but it is still susceptible to hacker attacks and has transmission distance and encryption rate limitations. This paper will discuss the flaws of quantum cryptographic systems along with the plans for enhancing current quantum cryptographic systems.