In my thesis I deal with quantum key distribution protocols.
Using symmetric-key encryption it is a problem to provide that the keys do not get to illegitimate user. However, there are methods based on quantum computing which can rule out the possibility of getting the key by a third-party. Some of these methods have been implemented and are used in practice.
When quantum key distribution protocols are discussed ideal environment is assumed in most of the cases. In my thesis I examine how the efficiency of the protocols change if they have to operate in a more realistic scheme. I use several environment and channel model to examine protocols. Using different parameters during the examination it can be figured out how the protocol sensitive for the change of different parameters (e. g. bit error rate).
In the beginning of my thesis I introduce the problem of classical key distribution. Following that I give a summary of quantum key distribution and describe some quantum key distribution protocols. In the second part I introduce an environment model which provides the opportunity to examine the protocols in a scenario differing from the idealistic.
In the last part of my thesis I summarize the results and draw consequences related to the effects of environment on the efficiency of quantum key distribution protocols.