This book is helpful for those readers who are willing to know about mobile agents that how mobile agents dispatch from one platform to another platform, what are its applications and how they work in real life.This book elaborates the concept of security in mobile agent systems that means how to prevent blocking attacks on mobile agents and also prevents the interpretation of mobile agent's data from malicious hosts.This book discusses various existing security approaches in mobile agent systems.Along this readers will also find a novel security to protect mobile agents from malicious hosts in mobile agent systems.In this book for readers i have also shown some simulation results that are implemented on aglets software.At the end for readers i have written appendix so that readers come to know how to install the aglets software development toolkit.