The project is guided by three goals: (1) iteratively design a set of concrete and interactive MR activities addressing key cybersecurity concepts (e.g., steganography, phishing, and firewalls) with teacher and student input throughout the design process; (2) increase student knowledge of key cybersecurity concepts, understanding of the importance of cybersecurity, and interest in cybersecurity careers; and (3) produce a set of design principles for MR activities in computing. MR activities will be iteratively refined based on observations, teacher interviews, and student survey feedback.