Access control in mobile ambient calculi: A comparative view

Ambient Calculi represent a class of process calculi used to describe and model mobile and distributed computations. This paper examines the most relevant of these calculi and focuses on an important dimension: the access control problem. In the security world, a system is considered trusted if it controls the access to its resources, i.e. every request for the access to a resource is honored if and only if the subject requiring the resource is an authorized user of the system and the request agrees with a given policy. So the security problem for ambient calculi is investigated considering the authentication mechanism and the possibility to implement security policies. Two examples have been chosen to illustrate these topics: the firewall and the communication by means of named channels.