Nowadays most of our sensitive information is accessible through web browsers. Securing these systems is of great concern, because any web accessible system is continuously exposed to threats. Internet, despite its important role in our lives today, is suffering from many drawbacks such as threats to confidential information, scam, fraud and even endangering users’ systems in the extreme.

Among the major concerns of large companies and private users regarding rogue java applets are destruction, modification and theft of their confidential documents. According to a Symantec Internet Security Threat Report there has been an overall increase in threats to confidential information. According to another Symantec Internet Security report published in October 2009 vulnerabilities in the Web browsers and Web browser plug-ins are causing attacks, attempting to gain access to a user system.

In this paper the basic security features of the Java platform, especially the Java Sandbox model security issues are discussed. Java Security Model (Sandbox) is one of the first and most popular security models that can be integrated into the Web browsers in order to prevent applets from doing anything destructive to the host system. Our ambition is ultimately to prove that the Java Sandbox Model is really secure, reliable and trustworthy security architecture.

The thesis is concluded by the findings that surely the Java Sandbox model provides mechanisms that can protect users’ confidential information from being stolen, deleted, modified and any other destructive external threads. The Sandbox model allows the users to take advantages of ad-hoc applications while it surrounds the running application to protect users’ system from malicious codes.