This report covers the work conducted within the National Institute of Standards and Technology's Computer Security Division during the Fiscal Year 2003. It discusses all projects and programs within the Division, staff highlights, and publications. For many years, the Computer Security Division (CSD) has made great contributions to help secure the Nation's sensitive information and information systems. CSD's work has paralleled the evolution of information technology (IT), initially focused principally on mainframe computers, to now encompass today's wide gamut of information technology devices. CSD's important responsibilities were re-affirmed by Congress with passage of the Federal Information Security Management Act (FIMSA) of 2002 and the Cyber Security Research and Development Act of 2002. Beyond the role to serve the Federal Agencies under FISMA, CSD standards and guidelines are often voluntarily used by U.S. industry, global industry, and foreign governments as sources of information and direction for securing information systems. CSD's research also contributes to securing the Nation's critical infrastructure systems. Moreover, the Division has an active role in both national and international standards organizations in promoting the interests of security and U.S. industry.