The goal of the paper is to analyse common problems of implementation of cryptographic algorithms, as well as to discuss some possibilities of implementing cryptographic algorithms in software development. In the paper, there are defined possible vulnerabilities in an implementation of cryptographic algorithms on a computer, and errors which are the causes of these vulnerabilities are classified. There are given general recommendations, how to escape from possible vulnerabilities. There is also considered implementation of cryptographic methods in software development by using software libraries and frameworks. Several widespread software frameworks which provide cryptographic functionality are compared with each other by several criteria (including the speed of execution of cryptographic algorithms). The goal of this comparison is to construct some guidelines which will help select a feasible solution for implementing a cryptographic functionality in software. Finally, there are discussed some general possibilities of maximising the speed of execution of cryptographic algorithms.