Calculation of the key length for quantum key distribution

Abstract

Quantum key distribution (QKD) is based on the laws of quantum physics and therefore it can guarantee the highest level of security. It is used to establish the key that is used for further symmetrical encryption. Since QKD consists of several phases in which the key is reduced, it is necessary to define the equation by which the length of the raw key is calculated. In this paper, we analyse all QKD phases with an emphasis on the explanation of the process of shortening the initial key. The results are verified with a large number of tests using a quantum cryptography simulator.