Current password authentication system was proven not secure enough to protect the information from intruders. However, various research has been done and the results show the value of FRR still low and the value of FAR still high. Thus, one of the methods suggests, is enhancing the current system using keystroke dynamics. Keystroke dynamics is a type of biometric authentication that does not require any special hardware, easy to use as the same routine as normal password authentication. Therefore, this research proposed an authentication system using keystroke dynamics to prevent the system from intruders. A system is developed that consist of two parts which are enrolment and verification. Then, a prototype is developed for testing process that consists of 3 main modules, namely Enrolment, Client/Server Connection and, Verification and Retraining. Based on the testing, the system proved that the keystroke dynamic authentication system was able to implement in client/server environment and shows the value of EER is low that indicates it provide a better system authentication. In future, the system can be improved by enhancing the security, performance, and user interface.