A Model of Access Control for Data Materials Based on Ambient Calculus

Enterprises such as companies, universities or institutes keep much documents, databases and/or softwares for their own functions. Such data materials should be managed properly. One of the important issues on management of materials is access control. This paper presents a formal model of access control of data materials in an organization that consists of a number of user groups. The model presented here is an extension of ambient calculus. As ambient calculus is introduced to model behavior of mobile systems such as agents accessing firewalls, it assumed that target systems have nested structures. We extend the calculus to represent unnested structures of user groups of materials. An example of user authentication protocol is presented.