infrastructure for heterogeneous networks. This infrastructure is inspired from the social trust model reflected in both mathematical heuristics and a communication protocol. It is with a view to optimize the cost of security, and therefore to use security means more effectively, that the trust infrastructure, which we distinguish from the security infrastructure, operates with the latter through the Trust-Security articulation. Finally, based on this articulation together with the security virtualization paradigm, we lay the foundations of a new security architecture taking into account the vertical heterogeneousness in addition to the horizontal heterogeneousness of networks.