Boxed Ambients (BA) replace Mobile Ambients' open capability with communication primitives acting across ambient boundaries. Expressiveness is achieved at the price of communication interferences on message reception whose resolution requires synchronisation of activities at multiple, distributed locations.
We study a variant of BA aimed at controlling communication interferences as well as mobility ones. Our calculus draws inspiration from Safe Ambients (SA) (with passwords) and modifies the communication mechanism of BA. Expressiveness is maintained through a new form of co-capability that at the same time registers incoming agents with the receiver ambient and performs access control.