Static control of code migration

This paper presents a type system to control the migration of code between sites in a concurrent distributed framework. The type system constitutes a decidable mechanism to ensure specific security policies, which control remote communication, process migration, and channel creation. The approach is as follows: each network administrator specifies sites privileges, and a type system checks that the processes running at those sites, as well as the composition of the sites, respect these policies. At runtime, well-typed networks do not violate the security policies declared for each site.