The theme of this book is an examination of security patterns for mobile agents systems and a unique weighting scheme for security patterns. It is motivated by the trend within software engineering, artificial intelligence to develop systems, which possess disconnects between security integration and system practicality. Security experts within software engineering are primarily concerned with the many facets of system security, while the mobile agent/distributed system developer is primarily concerned with building small commercial or academic prototypes systems that work for a particular research problem. This has led to the contemporary problem of ad-hoc mobile agent/distributed system development in disjointed pieces in which security is typically considered as an afterthought not as aforethought. Security patterns are a unique way to bridge the gap between practical secure systems, specialized prototype systems within the interdisciplinary fields of software engineering, and artificial intelligence. These security patterns allow the community to exploit the knowledge and experience of sophisticated members of their community as well as provide a framework for discussion.