The quality of software systems depends strongly on their architecture. For this reason, taking into account non-functional requirements at architecture level is crucial for the success of the software development process. Early architecture model validation facilitates the detection and correction of design errors. In this research, the authors are interested in security critical systems, which require a reliable validation process. So far, they are missing security-testing approaches providing an appropriate compromise between software quality and development cost while satisfying certification and audit procedures requirements through automated and documented validation activities. In this chapter, the authors propose a novel test-driven and architecture model-based security engineering approach for resilient systems. It consists of a test-driven security modeling framework and a test based validation approach. The assessment of the security requirement satisfaction is based on the test traces analysis. Throughout this study, the authors illustrate the approach using a client server architecture case study.