Mobile devices such as tab devices (e.g. iPad, Galaxy Tab), smart phones, laptops, and ultra-mobile personal computers (UMPCs) have become very popular as an access point of important information because of benefits such as small size and mobility. However, because of their high probability of loss or theft, it can turn into a point of information leakage. This is the reason why protection mechanism for confidential information stored in mobile devices have become a need. In this paper, a confidential information protection system for mobile devices is proposed, which is composed of a secure file system and a set of protocols. To show the security of our solution, we have performed an analysis of possible attacks. Additionally, we have developed client/server application prototypes using C# to demonstrate its implementation feasibility for a real environment. Copyright © 2012 John Wiley & Sons, Ltd.