NCSs

NCS stands for National Computer Security Center. It was a part of the United States Department of Defense's National Security Agency (NSA). The NCS was established in 1981 and its primary mission was to guide and manage the development of computer security standards for classified and sensitive unclassified government information systems. This effort was a response to the increasing reliance on computers for handling sensitive data and the growing concerns about the vulnerability of these systems to unauthorized access, modification, or destruction.

A significant contribution of the NCS was the development of the Trusted Computer System Evaluation Criteria (TCSEC), often referred to as the "Orange Book." This document provided a set of criteria for evaluating the security of computer systems. It categorized systems into different security levels, from A (highest) to D (lowest), based on their ability to protect information from unauthorized disclosure and ensure system integrity. The TCSEC became a widely recognized standard for computer security in both government and commercial sectors, influencing security practices and product development for many years.

The NCS also published other documents related to computer security, including guidelines on network security, data security, and risk management. These publications aimed to provide a comprehensive framework for securing information systems. While the NCS itself was later dissolved and its functions integrated into other NSA initiatives, its work laid important groundwork for the field of information security. The principles and standards established by the NCS continue to influence modern security practices and evaluation methods, highlighting its lasting impact on how secure computing is approached.