331 lines
16 KiB
Plaintext
331 lines
16 KiB
Plaintext
Computer User's 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 or 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 government
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and industry in the effective, safe, and economical use of
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computers. With the passage of the Computer Security
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Act of 1987 (P.L. 100-235), NIST's activities also include the
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development of standards and guidelines needed to assure the
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cost-effective security and privacy of sensitive information in
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Federal computer systems. This guide is just one of three
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brochures designed for a specific audience. The "Executive Guide
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to the Protection of Information Resources," and the "Managers
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Guide to the Protection of Information Resources" complete the
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series.
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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 of
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the National Institute of Standards and Technology.
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Introduction
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Today's computer technology, with microcomputers and on-line
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access, has placed the power of the computer where it belongs, in
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YOUR hands. YOU, the users, develop computer applications and
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perform other data processing functions which previously were
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only done by the computer operations personnel. These advances
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have greatly improved our efficiency and effectiveness but, also
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present a serious challenge in achieving adequate data security.
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While excellent progress has been made in computer technology,
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very little has been done to inform users of the vulnerability of
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data and information to such threats as unauthorized
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modification, disclosure, and destruction, either deliberate or
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accidental. This guide will make you aware of some of the
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undesirable things that can happen to data and will provide some
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practical solutions for reducing your risks to these threats.
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WHO IS RESPONSIBLE FOR PROTECTING DATA AND INFORMATION?
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The statement that "security is everyone's responsibility" is
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absolutely true. Owners, developers, operators and users of
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information systems each has a personal responsibility to protect
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these resources. Functional managers have the responsibility to
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provide appropriate security controls for any information
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resources entrusted to them. These managers are personally
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responsible for understanding the sensitivity and criticality of
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their data and the extent of losses that could occur if the
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resources are not protected. Managers must ensure that all users
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of their data and systems are made aware of the practices and
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procedures used to protect the information resources. When you
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don't know what your security responsibilities are, ASK YOUR
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MANAGER OR SUPERVISOR.
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WHAT IS "SENSITIVE" DATA?
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All data is sensitive to some degree; exactly how sensitive is
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unique to each business environment. Within the Federal
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Government, personal information is sensitive to unauthorized
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disclosure under the Privacy Act of 1974. In some cases, data is
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far more sensitive to accidental errors or omissions that
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compromise accuracy, integrity, or availability. For example, in
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a Management Information System, inaccurate, incomplete, or
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obsolete information can result in erroneous management decisions
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which could cause serious damage and require time and money to
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rectify. Data and information which are critical to an agency's
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ability to perform its mission are sensitive to nonavailability.
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Still other data are sensitive to fraudulent manipulation for
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personal gain. Systems that process electronic funds transfers,
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control inventories, issue checks, control accounts receivables
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and payables, etc., can be fraudulently exploited resulting in
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serious losses to an agency.
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One way to determine the sensitivity of data is to ask the
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questions "What will it cost if the data is wrong? Manipulated
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for fraudulent purposes? Not available? Given to the wrong
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person?" If the damage is more than you can tolerate, then the
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data is sensitive and should have adequate security controls to
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prevent or lessen the potential loss.
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WHAT RISKS ARE ASSOCIATED WITH THE USE OF COMPUTERS?
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Over the past several decades, computers have taken over
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virtually all of our major record-keeping functions. Recently,
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personal computers have made it cost-effective to automate many
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office functions. Computerization has many advantages and is here
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to stay; however, automated systems introduce new risks, and we
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should take steps to control those risks.
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We should be concerned with the same risks that existed when
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manual procedures were used, as well as some new risks created by
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the unique nature of computers themselves. One risk introduced by
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computers is the concentration of tremendous amounts of data in
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one location. The greater the concentration, the greater the
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consequences of loss or damage. Another example is that computer
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users access information from remote terminals. We must be able
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to positively identify the user, as well as ensure that the user
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is only able to access information and functions that have been
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authorized. Newspaper accounts of computer "hackers," computer
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virus attacks, and other types of intruders underscore the
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reality of the threat to government and commercial computer
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systems.
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HOW MUCH SECURITY IS ENOUGH?
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No matter how many controls or safeguards we use, we can never
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achieve total security. We can, however, decrease the risk in
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proportion to the strength of the protective measures. The degree
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of protection is based on the value of the information; in other
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words, how serious would be the consequences if a certain type of
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information were to be wrongfully changed, disclosed, delayed, or
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destroyed?
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General Responsibilities
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All Federal computer system users share certain general
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responsibilities for information resource protection. The
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following considerations should guide your actions.
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Treat information as you would any valuable asset.
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You would not walk away from your desk leaving cash or other
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valuables unattended. You should take the same care to protect
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information. If you are not sure of the value or sensitivity of
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the various kinds of information you handle, ask your manager for
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guidance.
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Use government computer systems only for lawful and authorized
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purposes.
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The computer systems you use in your daily work should be used
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only for authorized purposes and in a lawful manner. There are
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computer crime laws that prescribe criminal penalties for those
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who illegally access Federal computer systems or data.
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Additionally, the unauthorized use of Federal computer systems or
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use of authorized privileges for unauthorized purposes could
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result in disciplinary action.
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Observe policies and procedures established by agency
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management.
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Specific requirements for the protection of information have been
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established by your agency. These requirements may be found in
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policy manuals, rules, or procedures. Ask your manager if you are
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unsure about your own responsibilities for protection of
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information.
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Recognize that you are accountable for your activities on
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computer systems.
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After you receive authorization to use any Federal computer
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system, you become personally responsible and accountable for
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your activity on the system. Accordingly, your use should be
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restricted to those functions needed to carry out job
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responsibilities.
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Report unusual occurrences to your manager.
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Many losses would be avoided if computer users would report any
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circumstances that seem unusual or irregular. Warning signals
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could include such things as unexplainable system activity that
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you did not perform, data that appears to be of questionable
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accuracy, and unexpected or incorrect processing results. If you
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should notice anything of a questionable nature, bring it to your
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manager's attention.
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Security and Control Guidelines
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Some common-sense protective measures can reduce the risk of
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loss, damage, or disclosure of information. Following are the
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most important areas of information systems controls that assure
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that the system is properly used, resistant to disruptions, and
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reliable.
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Make certain no one can impersonate you.
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If a password is used to verify your identity, this is the key to
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system security. Do not disclose your password to anyone, or
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allow anyone to observe your password as you enter it during the
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sign-on process. If you choose your own password, avoid selecting
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a password with any personal associations, or one that is very
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simple or short. The aim is to select a password that would be
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difficult to guess or derive. "1REDDOG" would be a better
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password than "DUKE."
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If your system allows you to change your own password, do so
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regularly. Find out what your agency requires, and change
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passwords at least that frequently. Periodic password changes
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keep undetected intruders from continuously using the password of
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a legitimate user.
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After you are logged on, the computer will attribute all activity
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to your user id. Therefore, never leave your terminal without
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logging off -- even for a few minutes. Always log off or
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otherwise inactivate your terminal so no one could perform any
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activity under your user id when you are away from the area.
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Safeguard sensitive information from disclosure to others.
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People often forget to lock up sensitive reports and computer
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media containing sensitive data when they leave their work areas.
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Information carelessly left on top of desks and in unlocked
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storage can be casually observed, or deliberately stolen. Every
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employee who works with sensitive information should have
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lockable space available for storage when information is not in
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use. If you aren't sure what information should be locked up or
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what locked storage is available, ask your manager.
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While working, be aware of the visibility of data on your
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personal computer or terminal display screen. You may need to
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reposition equipment or furniture to eliminate over-the-shoulder
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viewing. Be especially careful near windows and in public areas.
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Label all sensitive diskettes and other computer media to alert
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other employees of the need to be especially careful. When no
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longer needed, sensitive information should be deleted or
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discarded in such a way that unauthorized individuals cannot
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recover the data. Printed reports should be finely shredded,
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while data on magnetic media should be overwritten. Files that
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are merely deleted are not really erased and can still be
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recovered.
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Install physical security devices or software on personal
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computers.
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The value and popularity of personal computers make theft a big
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problem, especially in low-security office areas. Relatively
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inexpensive hardware devices greatly reduce the risk of equipment
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loss. Such devices involve lock-down cables or enclosures that
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attach equipment to furniture. Another approach is to place
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equipment in lockable cabinets.
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When data is stored on a hard disk, take some steps to keep
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unauthorized individuals from accessing that data. A power lock
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device only allows key-holders to turn on power to the personal
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computer. Where there is a need to segregate information between
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multiple authorized users of a personal computer, additional
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security in the form of software is probably needed. Specific
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files could be encrypted to make them unintelligible to
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unauthorized staff, or access control software can divide storage
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space among authorized users, restricting each user to their own
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files.
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Avoid costly disruptions caused by data or hardware loss.
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Disruptions and delays are expensive. No one enjoys working
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frantically to re-enter work, do the same job twice, or fix
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problems while new work piles up. Most disruptions can be
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prevented, and the impact of disruptions can be minimized by
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advance planning. Proper environmental conditions and power
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supplies minimize equipment outages and information loss. Many
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electrical circuits in office areas do not constitute an adequate
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power source, so dedicated circuits for computer systems should
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be considered. Make certain that your surroundings meet the
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essential requirements for correct equipment operation. Cover
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equipment when not in use to protect it from dust, water leaks,
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and other hazards.
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For protection from accidental or deliberate destruction of data,
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regular data backups are essential. Complete system backups
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should be taken at intervals determined by how quickly
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information changes or by the volume of transactions. Backups
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should be stored in another location, to guard against the
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possibility of original and backup copies being destroyed by the
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same fire or other disaster.
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Maintain the authorized hardware/software configuration.
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Some organizations have been affected by computer "viruses"
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acquired through seemingly useful or innocent software obtained
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from public access bulletin boards or other sources; others have
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been liable for software illegally copied by employees. The
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installation of unauthorized hardware can cause damage,
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invalidate warranties, or have other negative consequences.
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Install only hardware or software that has been acquired through
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normal acquisition procedures and comply with all software
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licensing agreement requirements.
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SUMMARY
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Ultimately, computer security is the user's responsibility. You,
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the user, must be alert to possible breaches in security and
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adhere to the security regulations that have been established
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within your agency. The security practices listed are not
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inclusive, but rather designed to remind you and raise your
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awareness towards securing your information resources:
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PROTECT YOUR EQUIPMENT
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Keep it in a secure environment
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Keep food, drink, and cigarettes AWAY from it
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Know where the fire suppression equipment is located and know
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how to use it
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PROTECT YOUR AREA
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Keep unauthorized people AWAY from your equipment and data
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Challenge strangers in your area
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PROTECT YOUR PASSWORD
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Never write it down or give it to anyone
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Don't use names, numbers or dates which are personally
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identified with you
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Change it often, but change it immediately if you think it has
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been compromised
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PROTECT YOUR FILES
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Don't allow unauthorized access to your files and data
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NEVER leave your equipment unattended with your password
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activated - SIGN OFF!
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PROTECT AGAINST VIRUSES
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Don't use unauthorized software
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Back up your files before implementing ANY new software
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LOCK UP STORAGE MEDIA CONTAINING SENSITIVE DATA
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If the data or information is sensitive or critical to your
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operation, lock it up!
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BACK UP YOUR DATA
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Keep duplicates of your sensitive data in a safe place, out of
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your immediate area
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Back it up as often as necessary
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REPORT SECURITY VIOLATIONS
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Tell your manager if you see any unauthorized changes to your
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data
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Immediately report any loss of data or programs, whether
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automated or hard copy
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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
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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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