The concept that cybersecurity architecture is the discovery, definition and validation of rules is introduced. The new concept of inference graphs for illustrating the relationship between cybersecurity rules is defined. Three increasingly complex examples of inference graphs for systems needing cybersecurity architecture are presented, including the detailed proofs which form the basis of these inference graphs, in some cases. The software which has been developed to support the development and use of cybersecurity inference graphs is described including details of the public server where it can be used. It is shown that cybersecurity inference graphs can significantly contribute to development of, and validation of cybersecurity and also that rigorous validation of cybersecurity is not necessarily as difficult as previously thought.