This article discusses the problem of network authentication of a client when a functional web-system consists of various services, each of which is represented by a separate site. Particular attention is paid to Single Sign On technology - a single entry point as a way to achieve centralized authentication. A comparison of tools that provide a single input is given, and a conclusion is made about the best of them. Based on the research, the author proposes the Gluu single entry point server as a server that satisfies all the requirements of the functional service system presented in the example, and also able to work within the framework of popular authentication protocols.

Keywords: functional service system, authentication, authentication protocol, single entry point, single entry point server, comparative analysis