Implementation of secure architectures for mobile agents in MARISM-A. This paper introduces MARISM-A, an Architecture for Mobile Agents with Recursive Itinerary and Secure Migration. MARISM-A is a secure mobile agent platform providing complex security mechanisms to protect migration, confidentiality and integrity of agents. This is indeed one of the more novel features of this platform: itinerary, data and code of the agent are protected through a new model of mobile agents. Moreover, MARISM-A is extendable with user defined agent architectures. Mobile and nomadic computing can be implemented with MARISM-A, even though it has been specially designed to develop sea-of-data applications.