Splitting Mobility and Communication in Boxed Ambients

Stemming from our previous work on BACI, a boxed ambient calculus with communication in- terfaces, we define a new calculus that further enhances communication mechanisms and mobility control by introducing multiple communication ports, access control lists, and port hiding.The development of the calculus is mainly focused on three objectives: separation of concerns between mobility and communication, fine-grained controls, and locality. Communication primi- tives use ports to establish communication channels between ambients, while ambient names are only used for mobility. In order to achieve a better control over mobility, the calculus includes co-capabilities à la Safe Ambients, but with the addition of access control lists. These lists contain the names of the ambients that are allowed to enter or exit the ambient with that co-capability.The resulting calculus not only provides more flexibility and expressiveness than Boxed Ambients, but also enables simpler implementations using more powerful constructs for communication and mobility. We establish the basic meta-theory of the calculus by providing rules for type safety and showing that typing is preserved during execution.