Labelled mobile ambients model for information flow security in distributed systems

Abstract

Lattice model of secure information flow (referred as LIFS) is the foundation for building secure systems. In this paper, we capture the lattice model of security for mobility in a distributed setup using the formalism of Mobile Ambient calculus (MA) that has been widely used to model mobility and concurrency. Our model, referred to as Labelled Mobile Ambients (LMA), assigns labels to ambients for tracking information flow in the system, and provides semantics for preserving the distributed information flow policy specified by the labels. While there exist variants of the mobile ambient calculus for modelling application specific aspects of mandatory access control like confidentiality and integrity in the literature, our LMA model subsumes these models by capturing confidentiality and integrity as special cases of information flow properties. Thus, the LMA model enables a wide range of applications with complex security requirements, and permits a simple static analysis to establish whether the system violates information flow policy. A relative comparison to other prominent works is provided highlighting the merits of our LMA.