This handbook provides assistance in securing computer-based resources (including hardware, software, and information) by explaining important concepts, cost considerations, and interrelationships of security controls. It illustrates the benefits of security controls, the major techniques or approaches for each control, and important related considerations. The handbook provides a broad overview of computer security to help readers understand their computer security needs and develop a sound approach to the selection of appropriate security controls. It does not describe detailed steps necessary to implement a computer security program, provide detailed implementation procedures for security controls, or give guidance for auditing the security of specific systems.