Security solutions for networks typically appear as single protocols, or protocols that correspond to a single layer of the OSI network reference model (protocol stack). The result is a wide variety of protocols which provide solutions to very specific problems and environments. In this paper, we introduce an architecture for secure networks, which is based on layers, in analogy to the OSI protocol stack Adoption of a layered approach leads to many advantages in secure network design: modularity, flexibility, ease of standardization, etc. We introduce a reference model with 4 layers and argue that it is suitable for conventional network architectures. We present how layers of the secure network reference model correspond to layers of the OSI protocol stack, and we demonstrate that use of the layers leads to security solutions that resolve several problems of existing security protocols.