The aim of this thesis is, firstly, to design and create the measuring environment for the research of electromagnetic side-channel attacks in cryptography; and secondly, to inform readers about the basics of electromagnetic and power side-channel attacks which present effective ways of the modern cryptosystems’ cryptoanalysis. In the theoretical part, the basic side-channel attacks, including their history and models, are described. The main part is focused on the explanation of the basic principles of power and electromagnetic side-channel attacks. Then, the work describes the basic physical principles of electromagnetic fields; and also the methods which can be used to measure the electromagnetic field. An example of the origination of t...