E-Government can provide a citizen with better and/or more convenient services as opposed to the traditional government services. Application of electronic approach in completing an e-Procurement process opens up a lot of issues regarding security. The transparent nature of the process at hand is requiring a sophisticated security system. Unauthorized access or different kinds of intrusion present a legitimate threat. On the other hand, the attempt to develop such a system in developing countries like Serbia may face many difficulties. Some of the difficulties may be caused by legal obstacles, technical weaknesses, or human resistance towards change. This paper presents a review of authentication techniques used in the European e-Government systems and according to that this paper is focused on the methods we used to overcome those difficulties, as well as on the provision of a strong security system that would guarantee the protection of sensitive data.