The invention relates to a TEE (Trusted Environment Execution) structure which comprises: (a) a main domain defining a domain of operation for a main OS; (b) a privileged trusted domain defining a domain of operation for a trusted domain OS; and (c) a low level hypervisor which is separated from both of said main OS and said trusted domain OS, said hypervisor is used for: (c. 1) receiving packets from a network; (c.2) examining an address included in each of said received packets; and (c.3) based on the determined address in each of said packets, targeting respectively the packet to either said main OS or to said trusted domain OS, while in the latter case any interaction between the received packet and said main OS is eliminated.