This paper presents an upgrade of the libIEC61850 library in a way to implement a cryptographic key distribution mechanism that can be used within the library to protect communication through protocols such as GOOSE and SV. At the very beginning of the work, the IEC 61850 standard and its structure are described. The substation automation system for which the IEC 61850 standard is intended and its 3-level layout are presented and explained. Continuing on SAS, a brief overview of the data model used within it is given, a description of the communication mechanisms and protocols used to transfer data, as well as their mapping to protocols such as TCP, IP, UDP and others. The paper also contains a simple example of an SCL file that briefly presents the SCL used to define IEDs, the data transmitted in communication between them, and the entire communication within SAS. An insight into the security of the IEC 61850 standard is also given, in such a way that the threats and attacks on the systems that implement it are explained, as well as how to mitigate and prevent them using the IEC 62351 standard, which is intended to be a supplement to the mentioned standard. Since the practical part is based on it, the libIEC61850 library is briefly described and the running of one of the examples from it is shown. The implemented key distribution protocol was taken from [5] and is described as part of this paper. Finally, the paper contains the implementation method of the mentioned protocol, way to build implemented code examples and the demonstration of the implemented protocol.