This Information Security Handbook provides a broad overview of information security program elements to assist managers in understanding how to establish and implement an information security program. Typically, the organization looks to the program for overall responsibility to ensure the selection and implementation of appropriate security controls and to demonstrate the effectiveness of satisfying their stated security requirements. The topics within this document were selected based on the laws and regulations relevant to information security, including the Clinger-Cohen Act of 1996, the Federal Information Security Management Act (FISMA) of 2002, and Office of Management and Budget (OMB) Circular A-130. The material in this handbook can be referenced for general information on a particular topic or can be used in the decision-making process for developing an information security program. The purpose of this publication is to inform members of the information security management team about various aspects of information security that they will be expected to implement and oversee in their respective organizations. In addition, the handbook provides guidance for facilitating a more consistent approach to information security programs across the federal government. Even though the terminology in this document is geared toward the federal sector, the handbook can also be used to provide guidance on a variety of other governmental, organizational, or institutional security requirements. The intended audience includes agency heads, CIOs, SAISOs (also commonly referred to as CISOs), and security managers. The handbook provides information that the audience can use in building their information security program strategy. While there are differences between federal and private sector environments, especially in terms of priorities and legal requirements, the underlying principles of information security are the same. The handbook is therefore useful to any manager who requires a broad overview of information security practices.