Many contexts dealing with sensitive data are constantly looking for high assurance security solutions. The Multilevel Security represents one of the toughest unresolved problems faced over many years. Information and Communications systems need to exchange data, their software needs to be patched and updated hence, they need a connection to the Internet. Attacks can be launched using this connection, and through a compromised host attackers can steal and illicitly disclose information. In this paper we present a novel Multi Independent Levels of Security solution that enforces the separation of networks and data flow control through the use of a Separation Kernel Hypervisor. We show the robustness of our solution through a theoretical evaluation, supported by tools designed for the analysis of security protocols.