A thesis submitted in partial fulfillment of the requirement for the degree of Master of Engineering, School of Advanced Technologies

Thesis (M.Eng.) - Asian Institute of Technology, 1998

With the advent of Internet of technology, information sharing became much more rapid and important. World Wide Web has been used to build increasingly complex applications even the development was constrained by the static document model of Web. Development of Variety of mobile code systems such as Java, JavaScript, ActiveX eliminates the constrain faced by the Web application developer due to prior static document technique. Increasing popularity and acceptance of ·such mobile code systems have shifted the gravity of Web into a platform for writing complex mission critical applications, from its origin of simple HTML documents. On the other hand these mobile code or remote code, which rnns inside the environment supplied by the browser raises serious security threats. To address these security threats traditionally mobile code technology such as Java, JavaScript, ActiveX generally maintain a restricted security policy. There is a trade off between the openness desired by the Web application writer and security level imposed by the browser. In this work Java has been chosen as mobile code technology, as there are more Java Applets on the web than any other mobile code applications. This thesis presents a software-based extensible security architecture for Java Applets and proposes new model for Java Applets to support negotiation between the user and the Applet. Using this architecture a browser is built for preliminary evaluation.