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24 KiB
Plaintext
507 lines
24 KiB
Plaintext
Management Guide to the Protection of Information
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Resources
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National Institute of Standards and Technology
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The National Institute of Standards and Technology (NIST), is
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responsible for developing standards, providing technical
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assistance, and conducting research for computers and related
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systems. These activities provide technical support to
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government and industry in the effective, safe, and
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economical use of computers. With the passage of the Computer
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Security Act of 1987 (P.L. 100-235), NIST's activities also
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include the development of standards and guidelines needed to
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assure the cost-effective security and privacy of sensitive
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information in Federal computer systems. This guide represents
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one activity towards the protection and management of sensitive
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information resources.
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Acknowledgments
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This guide was written by Cheryl Helsing of Deloitte, Haskins &
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Sells in conjunction with Marianne Swanson and Mary Anne Todd,
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National Institute of Standards and Technology.
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Executive Summary
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Today computers are integral to all aspects of operations within
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an organization. As Federal agencies are becoming critically
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dependent upon computer information systems to carry out their
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missions, the agency executives (policy makers) are recognizing
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that computers and computer-related problems must be understood
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and managed, the same as any other resource. They are beginning
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to understand the importance of setting policies, goals, and
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standards for protection of data, information, and computer
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resources, and are committing resources for information security
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programs. They are also learning that primary responsibility for
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data security must rest with the managers of the functional areas
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supported by the data.
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All managers who use any type of automated information resource
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system must become familiar with their agency's policies and
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procedures for protecting the information which is processed and
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stored within them. Adequately secure systems deter, prevent, or
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detect unauthorized disclosure, modification, or use of
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information. Agency information requires protection from
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intruders, as well as from employees with authorized computer
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access privileges who attempt to perform unauthorized actions.
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Protection is achieved not only by technical, physical and
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personnel safeguards, but also by clearly articulating and
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implementing agency policy regarding authorized system use to
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information users and processing personnel at all levels. This
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guide is one of three brochures that have been designed for a
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specific audience. The "Executive Guide to the Protection of
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Information Resources" and the "Computer User's Guide to the
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Protection of Information Resources" complete the series.
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Table of Contents
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Executive Summary iv
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Introduction 1
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Purpose of Guide 1
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The Risks 1
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Responsibilities 2
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Information Systems Development 5
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Control Decisions 5
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Security Principles 5
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Access Decisions 7
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Systems Development Process 7
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Computer Facility Management 9
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Physical Security 9
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Data Security 11
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Monitoring and Review 11
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Personnel Management 13
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Personnel Security 13
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Training 14
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For Additional Information 15
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Introduction
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Purpose of this Guide
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This guide introduces information systems security concerns and
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outlines the issues that must be addressed by all agency managers
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in meeting their responsibilities to protect information systems
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within their organizations. It describes essential components of
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an effective information resource protection process that applies
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to a stand alone personal computer or to a large data processing
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facility.
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The Risks
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Effort is required by every Federal agency to safeguard
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information resources and to reduce risks to a prudent level.
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The spread of computing power to individual employees via
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personal computers, local-area networks, and distributed
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processing has drastically changed the way we manage and control
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information resources. Internal controls and control points that
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were present in the past when we were dealing with manual or
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batch processes have not been established in many of today's
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automated systems. Reliance upon inadequately controlled computer
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systems can have serious consequences, including:
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Inability or impairment of the agency's ability to perform its
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mission
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Inability to provide needed services to the public
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Waste, loss, misuse, or misappropriation of funds
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Loss of credibility or embarrassment to an agency
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To avoid these consequences, a broad set of information security
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issues must be effectively and comprehensively addressed.
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Responsibilities
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All functional managers have a responsibility to implement the
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policies and goals established by executive management for
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protection of automated information resources (data, processes,
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facilities, equipment, personnel, and information). Managers in
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all areas of an organization are clearly accountable for the
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protection of any of these resources assigned to them to enable
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them to perform their duties. They are responsible for
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developing, administering, monitoring, and enforcing internal
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controls, including security controls, within their assigned
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areas of authority. Each manager's specific responsibilities will
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vary, depending on the role that manager has with regard to
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computer systems.
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Portions of this document provide more detailed information on
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the respective security responsibilities of managers of computer
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resources, managers responsible for information systems
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applications and the personnel security issues involved.
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However, all agency management must strive to:
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Achieve Cost-Effective Security
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The dollars spent for security measures to control or contain
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losses should never be more than the projected dollar loss if
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something adverse happened to the information resource.
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Cost-effective security results when reduction in risk through
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implementation of safeguards is balanced with costs. The greater
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the value of information processed, or the more severe the
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consequences if something happens to it, the greater the need
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for control measures to protect it.
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The person who can best determine the value or importance of
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data is the functional manager who is responsible for the data.
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For example, the manager responsible for the agency's budget
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program is the one who should establish requirements for the
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protection of the automated data which supports the program. This
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manager knows better than anyone else in the organization what
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the impact will be if the data is inaccurate or unavailable.
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Additionally, this manager usually is the supervisor of most of
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the users of the data.
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It is important that these trade-offs of cost versus risk
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reduction be explicitly considered, and that management
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understand the degree of risk remaining after selected controls
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are implemented.
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Assure Operational Continuity
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With ever-increasing demands for timely information and greater
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volumes of information being processed, the threat of information
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system disruption is a very serious one. In some cases,
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interruptions of only a few hours are unacceptable. The impact
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due to inability to process data should be assessed, and actions
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should be taken to assure availability of those systems
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considered essential to agency operation. Functional management
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must identify critical computer applications and develop
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contingency plans so that the probability of loss of data
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processing and telecommunications support is minimized.
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Maintain Integrity
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Integrity of information means you can trust the data and the
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processes that manipulate it. Not only does this mean that errors
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and omissions are minimized, but also that the information system
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is protected from deliberate actions to wrongfully change the
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data. Information can be said to have integrity when it
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corresponds to the expectations and assumptions of the users.
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Assure Confidentiality
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Confidentiality of sensitive data is often, but not always, a
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requirement of agency systems. Privacy requirements for personal
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information is dictated by statute, while confidentiality of
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other agency information is determined by the nature of that
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information, e.g., information submitted by bidders in
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procurement actions. The impact of wrongful disclosure must be
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considered in understanding confidentiality requirements.
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Comply with Applicable Laws and Regulations
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As risks and vulnerabilities associated with information systems
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become better understood, the body of law and regulations
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compelling positive action to protect information resources
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grows. OMB Circular No. A-130, "Management of Federal
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Information Resources" and Public Law 100-235, "Computer Security
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Act of 1987" are two documents where the knowledge of these
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regulations and laws provide a baseline for an information
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resource security program.
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Information Systems Development
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This section describes the protective measures that should be
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included as part of the design and development of information
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processing application systems. The functional manager that is
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responsible for and will use the information contained in the
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system, must ensure that security measures have been included and
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are adequate. This includes applications designed for personal
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computers as well as large mainframes.
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Control Decisions
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The official responsible for the agency function served by the
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automated information system has a critical role in making
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decisions regarding security and control. In the past, risk was
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often unconsciously accepted when such individuals assumed the
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computer facility operators were taking care of security. In
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fact, there are decisions to be made and security elements to be
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provided that cannot be delegated to the operator of the system.
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In many cases, the user or manager develops the application and
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operates solely.
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The cost of control must be balanced with system efficiency and
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usability issues. Risk must be evaluated and cost-effective
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controls selected to provide a prudent level of control while
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maximizing productivity. Controls are often closely connected
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with the system function, and cannot be effectively designed
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without significant understanding of the process being automated.
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Security Principles
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There are some common security attributes that should be present
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in any system that processes valuable personal or sensitive
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information. System designs should include mechanisms to enforce
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the following security attributes.
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Identification and Authentication of Users
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Each user of a computer system should have a unique
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identification on the system, such as an account number or other
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user identification code. There must also be a means of verifying
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that the individual claiming that identity (e.g., by typing in
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that identifying code at a terminal) is really the authorized
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individual and not an imposter. The most common means of
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authentication is by a secret password, known only to the
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authorized user.
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Authorization Capability Enforcing the Principle of Least
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Possible Privilege
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Beyond ensuring that only authorized individuals can access the
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system, it is also necessary to limit the users access to
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information and transaction capabilities. Each person should be
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limited to only the information and transaction authority that is
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required by their job responsibilities. This concept, known as
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the principle of least possible privilege, is a long-standing
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control practice. There should be a way to easily assign each
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user just the specific access authorities needed.
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Individual Accountability
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From both a control and legal point of view, it is necessary to
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maintain records of the activities performed by each computer
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user. The requirements for automated audit trails should be
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developed when a system is designed. The information to be
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recorded depends on what is significant about each particular
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system. To be able to hold individuals accountable for their
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actions, there must be a positive means of uniquely identifying
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each computer user and a routinely maintained record of each
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user's activities.
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Audit Mechanisms
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Audit mechanisms detect unusual events and bring them to the
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attention of management. This commonly occurs by violation
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reporting or by an immediate warning to the computer system
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operator. The type of alarm generated depends on the seriousness
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of the event.
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A common technique to detect access attempts by unauthorized
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individuals is to count attempts. The security monitoring
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functions of the system can automatically keep track of
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unsuccessful attempts to gain access and generate an alarm if the
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attempts reach an unacceptable number.
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Performance Assurance
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A basic design consideration for any information system should
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be the ability to verify that the system is functioning as
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intended. Systems that are developed without such design
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considerations are often very difficult to independently audit or
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review, leading to the possibility of unintended results or
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inaccurate processing.
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Recoverability
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Because Federal agencies can potentially be heavily dependent on
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a computer system, an important design consideration is the
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ability to easily recover from troublesome events, whether minor
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problems or major disruptions of the system. From a design point
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of view, systems should be designed to easily recover from minor
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problems, and to be either transportable to another backup
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computer system or replaced by manual processes in case of major
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disruption or loss of computer facility.
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Access Decisions
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Once the automated system is ready to use, decisions must be
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made regarding access to the system and the information it
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contains. For example, many individuals require the ability to
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access and view data, but not the ability to change or delete
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data. Even when computer systems have been designed to provide
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the ability to narrowly designate access authorities, a
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knowledgeable and responsible official must actually make those
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access decisions. The care that is taken in this process is a
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major determining factor of the level of security and control
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present in the system. If sensitive data is being transmitted
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over unprotected lines, it can be intercepted or passive
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eavesdropping can occur. Encrypting the files will make the data
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unintelligible and port protection devices will protect the files
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from unauthorized access, if warranted.
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Systems Development Process
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All information systems software should be developed in a
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controlled and systematic manner according to agency standards.
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The quality and efficiency of the data processed, and the
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possible reconfiguration of the system can all be affected by an
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inadequate development process. The risk of security exposures
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and vulnerabilities is greatly reduced when the systems
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development process is itself controlled.
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Computer Facility Management
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Functional managers play a critical role in assuring that agency
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information resources are appropriately safeguarded. This section
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describes the protective measures that should be incorporated
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into the ongoing management of information resource processing
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facilities. As defined in OMB Circular No. A-130, "Management of
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Federal Information Resources," the term "information technology
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facility" means an organizationally defined set of personnel,
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hardware, software, and physical facilities, a primary function
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of which is the operation of information technology. This
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section, therefore applies to any manager who houses a personal
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computer, mainframe or any other form of office system or
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automated equipment.
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Physical Security
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Information cannot be appropriately protected unless the
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facilities that house the equipment are properly protected from
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physical threats and hazards. The major areas of concern are
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described below.
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Environmental Conditions
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For many types of computer equipment, strict environmental
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conditions must be maintained. Manufacturer's specifications
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should be observed for temperature, humidity, and electrical
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power requirements.
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Control of Media
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The media upon which information is stored should be carefully
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controlled. Transportable media such as tapes and cartridges
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should be kept in secure locations, and accurate records kept of
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the location and disposition of each. In addition, media from an
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external source should be subject to a check-in process to ensure
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it is from an authorized source.
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Control of Physical Hazards
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Each area should be surveyed for potential physical hazards.
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Fire and water are two of the most damaging forces with regard to
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computer systems. Opportunities for loss should be minimized by
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an effective fire detection and suppression mechanism, and
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planning reduces the danger of leaks or flooding. Other physical
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controls include reducing the visibility of the equipment and
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strictly limiting access to the area or equipment.
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Contingency Planning
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Although risks can be minimized, they cannot be eliminated. When
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reliance upon a computer facility or application is substantial,
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some type of contingency plan should be devised to allow critical
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systems to be recovered following a major disaster, such as a
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fire. There are a number of alternative approaches that should be
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evaluated to most cost-effectively meet the agency's need for
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continuity of service.
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Configuration Management
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Risk can be introduced through unofficial and unauthorized
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hardware or software. Another key component of information
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resource management is ensuring only authorized hardware and
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software are being utilized. There are several control issues to
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be addressed.
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Maintaining Accurate Records
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Records of hardware/software inventories, configurations, and
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locations should be maintained and kept up-to-date.
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Complying with Terms of Software Licenses
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Especially with microcomputer software, illegal copying and
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other uses in conflict with licensing agreements are concerns.
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The use of software subject to licensing agreements must be
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monitored to ensure it is used according to the terms of the
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agreement.
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Protecting Against Malicious Software and Hardware
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The recent occurrences of destructive computer "viruses" point
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to the need to ensure that agencies do not allow unauthorized
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software to be introduced to their computer environments.
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Unauthorized hardware can also contain hidden vulnerabilities.
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Management should adopt a strong policy against unauthorized
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hardware/software, inform personnel about the risks and
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consequences of unauthorized additions to computer systems, and
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develop a monitoring process to detect violations of the policy.
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Data Security
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Management must ensure that appropriate security mechanisms are
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in place that allow responsible officials to designate access to
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data according to individual computer users' specific needs.
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Security mechanisms should be sufficient to implement individual
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authentication of system users, allow authorization to specific
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information and transaction authorities, maintain audit trails as
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specified by the responsible official, and encrypt sensitive
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files if required by user management.
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Monitoring and Review
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A final aspect of information resource protection to be
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considered is the need for ongoing management monitoring and
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review. To be effective, a security program must be a continuous
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effort. Ideally, ongoing processes should be adapted to include
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information protection checkpoints and reviews. Information
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resource protection should be a key consideration in all major
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computer system initiatives.
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Earlier, the need for system audit trails was discussed. Those
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audit trails are useful only if management regularly reviews
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exception items or unusual activities. Irregularities should be
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researched and action taken when merited. Similarly, all
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information-related losses and incidents should be investigated.
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A positive benefit of an effective monitoring process is an
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increased understanding of the degree of information-related risk
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in agency operations. Without an ongoing feedback process,
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management may unknowingly accept too much risk. Prudent
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decisions about trade-offs between efficiency and control can
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only be made with a clear understanding of the degree of inherent
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risk. Every manager should ask questions and periodically review
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operations to judge whether changes in the environment have
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introduced new risk, and to ensure that controls are working
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effectively.
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Personnel Management
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Managers must be aware that information security is more a
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people issue than a technical issue. Personnel are a vital link
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in the protection of information resources, as information is
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gathered by people, entered into information resource systems by
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people, and ultimately used by people. Security issues should be
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addressed with regard to:
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People who use computer systems and store information in the
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course of their normal job responsibilities
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People who design, program, test, and implement critical or
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sensitive systems
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People who operate computer facilities that process critical or
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sensitive data
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Personnel Security
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From the point of hire, individuals who will have routine access
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to sensitive information resources should be subject to special
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security procedures. More extensive background or reference
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checks may be appropriate for such positions, and security
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responsibilities should be explicitly covered in employee
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orientations. Position descriptions and performance evaluations
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should also explicitly reference unusual responsibilities
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affecting the security of information resources.
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Individuals in sensitive positions should be subject to job
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rotation, and work flow should be designed in such a way as to
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provide as much separation of sensitive functions as possible.
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Upon decision to terminate or notice of resignation, expedited
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termination or rotation to less sensitive duties for the
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remainder of employment is a reasonable precaution.
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Any Federal computer user who deliberately performs or attempts
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to perform unauthorized activity should be subject to
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disciplinary action, and such disciplinary action must be
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uniformly applied throughout the agency. Any criminal activity
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under Federal or state computer crime laws must be reported to
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law enforcement authorities.
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Training
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Most information resource security problems involve people.
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Problems can usually be identified in their earliest stages by
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people who are attuned to the importance of information
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protection issues. A strong training program will yield large
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benefits in prevention and early detection of problems and
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losses. To be most effective, training should be tailored to the
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particular audience being addressed, e.g., executives and policy
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makers; program and functional managers; IRM security and audit:
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ADP management and operations; end users.
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Most employees want to do the right thing, if agency
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expectations are clearly communicated. Internal policies can be
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enforced only if staff have been made aware of their individual
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responsibilities. All personnel who access agency computer
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systems should be aware of their responsibilities under agency
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policy, as well as obligations under the law. Disciplinary
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actions and legal penalties should be communicated.
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For Additional Information
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National Institute Of Standards and Technology
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Computer Security Program Office, A-216 Technology
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Gaithersburg, MD 20899
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(301) 975-5200
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For further information on the management of information
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resources, NIST publishes Federal Information Processing
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Standards Publications (FIBS PUBS). These publications deal with
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many aspects of computer security, including password usage, data
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encryption, ADP risk management and contingency planning, and
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computer system security certification and accreditation. A list
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of current publications is available from:
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Standards Processing Coordinator (ADP)
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National Computer Systems Laboratory
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National Institute of Standards and Technology
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Technology Building, B-64
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Gaithersburg, MD 20899
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Phone: (301) 975-2817
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