Information Flow Security in Mobile Ambients

A multilevel security policy is considered in the scenario of mobile systems, and modeled within "pure" Mobile Ambients calculus, in which no communication channels are present and the only possible actions are represented by the moves performed by mobile processes. The information flow property of interest is defined in terms of the possibility for a confidential ambient/data to move outside a security boundary. Then, a very simple syntactic property is given that is sufficient to imply the absence of unwanted information flows.