Password based logon schemes have many security weaknesses. For secure environments smart card and biometric based authentication solutions are available as replacement for standard password based systems. Nevertheless, the cost of deployment and maintenance of these systems is quite high. On the other hand, mobile network operators have a huge base of deployed smart cards that can be reused to provide authentication in other spheres significantly reducing costs. In this project we present a study of how mobile phones can be used to provide a secure low-cost two-factor workstation logon solution.To find and study the available mobile phone based authentication architectures and come up with workstation logon architecture the study of relevant technologies utilized in these solutions, authentication and authorization in Windows, Linux, and MAC OS X. The analysis of available mobile phone based authentication schemes like SIM Strong schemes based on EAP-SIM, Session-ID based schemes, and OTP based schemes are also added.A solution for Linux workstation logon process has been proposed in the thesis using the PAM. The Solution uses 2 factors for authentication.