The need for trustworthy secure systems stems from a wide variety of needs driven by missions, business, governments, and a spectrum of other objectives. Today’s systems have dimensions and complexity that require disciplined and a structured engineering approach to achieve expectations that can be effectively managed within feasible limits of human capability. Managing the complexity of today’s systems and being able to claim they are trustworthy and secure regards the ability of a system to function securely as intended. Having a strong basis provides the foundation to address any of the additional security concerns to provide confidence for the expectation the system functions as intended across spectrums of disruptions, hazards, and threats. Security engineering provides a strong foundation for a disciplined and secured approach to creating trustworthy secure systems. Systems security engineering, when properly integrated, provides the needed complementary engineering capability to extend notions of trustworthiness to deliver secure and trusty systems. The effects of disruptions, hazards, and threats to include sophisticated cyber-attacks can be reduced or controlled by well-defined security design principles, concepts, and techniques which system security engineers and activities are based. Having a greater level of trustworthiness in a system means it is possible to put procedures in place to to help individuals respond more effectively to attacks and other disruptions. Security engineering contributes to a broad holistic security perspective. This ensures stakeholder protection needs and security concerns associated with systems are properly identified and addressed. This may include the protection of intellectual/private property in the form of data, information, techniques, and technology used to create the system or is incorporated into the system. Security engineering activities draw upon the combination of well-established engineering systems, security principles, and concepts to create relevant principles and practices for system engineering. Overall engineers create a safer cyber network by creating systems that protect our information and to make sure they work properly function in the ways they were designed.