In this day and age, mobile devices are developed to serve various functions; storing sensitive information such as passwords, bank credentials, and important data. As a consequence, authenticating users for mobile devices has become an important issue. However, unlike desktops and notebook computers, a four digit personal identification number (PIN), is often adopted as the sole security mechanism for mobile devices. Due to their limited length, PINs are vulnerable to surfing and systematic trial-and-error attacks. Additionally, the development of the mobile system is moving forward to touch screen system for user-friendly and quick access mechanism. This thesis project is one of the two related thesis projects that demonstrate the effectiveness of user authentication using keystroke dynamics-based authentication on mobile devices. Key down, key up times and the key ASCII codes are the inputs captured from the user typing. Four features, (key code, two keystroke latencies, and key duration) are analyzed while capturing samples from the user and stored in the database in a format; which is easily used by a related thesis project. The stored samples are then compared with the current sample using an algorithm to authenticate users. Google Android is used as a development platform for implementation.