Types as Specifications of Access Policies

Mobility is a key concept for network programming; it has stimulated much research about new programming languages and paradigms. In the design of programming languages for mobile agents, i.e. processes which can migrate and execute on new hosts, the integration of security mechanisms is a major challenge. This paper presents the security mechanisms of the programming language Klaim (a Kernel Language for Agents Interaction and Mobility). The language, by making use of a capability-based type system, provides direct support for expressing and enforcing policies that control access to resources and data