The mobile agent computing and mobile agent-mediated e-business fields are exciting research areas which are full of potential and challenges. This research is prompted by two natural observations. On the one side, there are many computing paradigms available to support multiple hosts to communicate over a network such as client-server remote procedure calling, remote evaluation, code-on-demand, and object migration. So, why does the mobile agent paradigm still attract continued attention from the distributed computing community? Is there any peculiar application for the mobile agent paradigm that makes it outperforming all other existing technologies? On the other side, e-business has become more prominent in recent years. With the rapid development of information technology and the widespread popularity of the Internet, various techniques, such as Applets, Servlets, Common Gateway Interface, and Java Server Page, have been proven successful to help online businesses enhance their network functions. Therefore, what is the justification of employing mobile agents for e-business applications? And why is there no commercialised system so far to support mobile agent-mediated e-business in reality? This study seeks to give a deeper analysis and discussion on these questions and work out meaningful solutions. Two types of people may have special interests in this research. One is the distributing system designer: the analysis of advantages and disadvantages of mobile agent computing may assist them to choose the best available paradigm to achieve communication efficiency for network computing. The other is the e-business application developer: the proposed e-business models, design patterns and protection structures may convince them to employ mobile agents in the future for their business service improvement. In this thesis, mobile agent computing is examined in two perspectives: the evolution of mobile agent paradigm, and the development of mobile agent platform. One major reason for this arrangement is that mobile agent technology is believed to have a natural evolution from a set of earlier technologies, and at the same time adds some new characteristics specific to the mobile agent world (e.g., disconnected operation and autonomous migration). Still most of these advantages have to be facilitated by the underlying execution platform. The advantages and novelty of using mobile agents for e-business construction are analysed in three parts. Firstly, a collection of mobile agent-mediated e-business models is proposed. These models seek to help online businesses make use of agent-specific features to automate their transactions and improve their quality of service. Secondly, the applicability of employing competitive analysis for mobile agent-oriented decision-making is explored, with a view to improving a mobile agent's adaptability in an online environment with the guide of an optimised competitive ratio. Finally, a group of agent-based patterns for e-business system design is proposed, aimed at encapsulating empirical experiences and domain knowledge to avoid similar problem-solving strategies being constantly reinvented.
While mobile agent technology brings great potential to the e-business field, a series of challenging problems also arises. The most serious of these is with regards to security. Without a proper security structure or protection scheme, one cannot expect mobile agents to be quickly adopted for commercial uses. In this thesis, mobile agent protection in an Internet-based e-business system is investigated. A number of agent-protection structures are suggested to enhance an agent's self-protecting capability in a competitive computing environment, as well as increase protection strength and lower development cost. In the conclusion, several future directions are suggested.