Summary: Causal Type System for Ambient Movements #
Torben Amtoft ##
Heriot­Watt University
tamtoft@cee.hw.ac.uk
www.cee.hw.ac.uk/~tamtoft
Abstract. The Ambient Calculus was developed by Cardelli and Gor­
don as a formal framework to study issues of mobility and migrant code.
We present a type system for the calculus, parameterized by security con­
straints expressing where a given ambient may reside and where it may
be dissolved. A subject reduction property then guarantees that a well­
typed process never violates these constraints; additionally it ensures
that communicating subprocesses agree on their ``topic of conversation''.
Based on techniques borrowed from finite automata theory, type check­
ing of type­annotated processes is decidable. Under certain quite natural
restrictions, type inference is also possible.
The type system employs a notion of causality in that processes are
assigned ``behaviors''. This significantly increases the precision of the
analysis and compensates for the lack of ``co­capabilities'' (an otherwise
increasingly popular extension to the ambient calculus); also it allows an
ambient to hold multiple topics of conversation.

Source: Amtoft, Torben - Department of Computing and Information Sciences, Kansas State University

Collections: Computer Technologies and Information Sciences