The Rainbow Books


NCSC-TG-027

Library No. 5-238,461

Version-I

FOREWORD

The National Computer Security Center is issuing A Guide to Understanding Information 
System Security Officer Responsibilities for Automated Information Systems as part of the 
"Rainbow Series" of documents our Technical Guidelines Program produces. In the Rainbow 
Series, we discuss in detail the features of the Department of Defense Trusted Computer System 
Evaluation Criteria (DOD 5200.28-STD) and provide guidance for meeting each requirement. The 
National Computer Security Center, through its Trusted Product Evaluation Program, evaluates the 
security features of commercially-produced computer systems. Together, these programs ensure 
that organizations are capable of protecting their important data with trusted computer systems.

A Guide to Understanding Information System Security Officer Responsibilities for 
Automated Information Systems helps Information System Security Officers (ISSOs) understand 
their responsibilities for implementing and maintaining security in a system. The system may be a 
remote site linked to a network, a stand-alone automated information system, or workstations 
interconnected via a local area network. This guideline also discusses the roles and responsibilities 
of other individuals who are responsible for security and their relationship to the ISSO, as defined 
in various component regulations and standards.

I invite your suggestions for revising this document. We plan to review this document as the 
need arises.

	May 1992





Patrick R. Gallagher, Jr.
Director
National Computer Security Center

ACKNOWLEDGMENTS

The National Computer Security Center extends special recognition for their contributions to 
this document to Annabelle Lee as principal author, to Ellen E. Flahavin and Carol L. Lane as 
contributing authors and project managers, and to Monica L. Collins as project manager.

We also thank the many representatives from the computer security community who gave of 
their time and expertise to review the guideline and provide comments and suggestions. Special 
thanks are extended to First Lieutenant Pamela D. Miller, United States Air Force, for her thought 
provoking suggestions and comments.

TABLE OF CONTENTS

FOREWORD			

ACKNOWLEDGMENTS			

LIST OF TABLES			

1. INTRODUCTION				

	1.1	Security Regulations, Policies, and Standards		
		 1.1.1	Federal Regulations	
		 1.1.2	Department of Defense Security Policy	
		 1.1.3	Security Standards	
	1.2	Purpose		
	1.3	Structure of the Document		

2. OPERATIONAL ENVIRONMENT			7
	 2.1 Type of Information Processed			
		2.1.1	Unclassified	
		2.1.2	Sensitive Unclassified	
		2.1.3	Confidential	
		2.1.4	Secret	
		2.1.5	Top Secret	
	 2.2 Security Mode of Operation			
		2.2.1	Dedicated Security Mode	
		2.2.2	System High Security Mode	
		2.2.3	Partitioned Security Mode	
		2.2.4	Compartmented Security Mode	
		2.2.5	Multilevel Security Mode	

3. ISSO AREAS OF RESPONSIBILITY				
	3.1	ISSO Technical Qualifications		
	3.2	Overview of ISSO Responsibilities		
	3.3	ISSO Security Responsibilities		
	3.4	Security Regulations and Policies		
	3.5	Mission Needs		
	3.6	Physical Security Requirements		

		 3.6.1	Contingency Plans	
		 3.6.2	Declassification and Downgrading of Data and Equipment	
	3.7	Administrative Security Procedures		
		 3.7.1	Personnel Security	
		 3.7.2	Security Incidents Reporting	
		 3.7.3	Termination Procedures	
	3.8	Security Training		
	3.9	Security Configuration Management		

	3.10	Access	Control	
		3.10.1	Facility Access	
		3.10.2	Identification and Authentication (I&A)	
		3.10.3	Data Access	
	3.11	Risk Management		
	3.12	Audits		
		3.12.1	Audit Trails	
		3.12.2	Auditing Responsibilities	
	3.13	Certification and Accreditation		

4. SECURITY PERSONNEL ROLES			
	4.1	Designated Approving Authority (DAA)	
	4.2	Component Information System Security Manager (CISSM)	
	4.3	Information System Security Manager (ISSM)	
	4.4	Network Security Manager (NSM)	
	4.5	Information System Security Officer (ISSO)	
	4.6	Network Security Officer (NSO)	
	4.7	Terminal Area Security Officer (TASO)	
	4.8	Security Responsibilities of Other Site Personnel	
	4.9	Assignment of Security Responsibilities	

BIBLIOGRAPHY	
REFERENCES	
ACRONYMS	
GLOSSARY	

LIST OF TABLES

TABLE NUMBER			PAGE

1.	Service and Agency Security Personnel Titles		
2.	Uniform Security Personnel Titles		
3.	Function Matrix		

1.	INTRODUCTION

This guideline identifies system security responsibilities for Information System Security 
Officers (ISSOs). It applies to computer security aspects of automated information systems (AISs) 
within the Department of Defense (DOD) and its contractor facilities that process classified and 
sensitive unclassified information. Computer security (COMPUSEC) includes controls that protect 
an AIS against denial of service and protects the AISs and data from unauthorized (inadvertent or 
intentional) disclosure, modification, and destruction. COMPUSEC includes the totality of 
security safeguards needed to provide an acceptable protection level for an AIS and for data 
handled by an AIS. [1] DOD Directive (DODD) 5200.28 defines an AIS as "an assembly of 
computer hardware, software, and/or firmware configured to collect, create, communicate, 
compute, disseminate, process, store, and/or control data or information." [2] This guideline is 
consistent with established DOD regulations and standards, as discussed in the following sections. 
Although this guideline emphasizes computer security, it is important to ensure that the other 
aspects of information systems security, as described below, are in place and operational:

	Physical security includes controlling access to facilities that contain classified and 
sensitive unclassified information. Physical security also addresses the protection of the 
structures that contain the computer equipment.

	Personnel security includes the procedures to ensure that access to classified and sensitive 
unclassified information is granted only after a determination has been made about a 
person's trustworthiness and only if a valid need-to-know exists.

Need-to-know is the necessity for access to, knowledge of, or possession of specific 
information required to perform official tasks or services. The custodian, not the 
prospective recipient(s), of the classified or sensitive unclassified information determines 
the need-to-know.

	Administrative security addresses the management constraints and supplemental controls 
needed to provide an acceptable level of protection for data. These constraints and 
procedures supplement the security procedures implemented in the computer and network 
systems.

	Communications security (COMSEC) defines measures that are taken to deny 
unauthorized persons information derived from telecommunications of the U.S. 
Government concerning national security and to ensure the authenticity of such 
telecommunications. [1]

	Emissions security is the protection resulting from all measures taken to deny unauthorized 
persons information of value which might be derived from intercept and analysis of 
compromising emanations from crypto-equipment, AISs, and telecommunications 
systems.

All these security areas are vital to the operation of a secure system. This guideline focuses 
on computer security, with discussions of the other security topics, as applicable.

1.1	SECURITY REGULATIONS, POLICIES, AND STANDARDS

This section provides an overview of regulations, policies, and criteria that address security 
requirements.

1.1.1	FEDERAL REGULATIONS

National mandates require the protection of sensitive information, as listed below:

	Title 18, U.S. Code 1905, makes it unlawful for any office or employee of the U.S. 
Government to disclose information of an official nature except as provided by law, 
including data processed by computer systems.

	Office of Management and Budget (OMB) Circular No. A-1 30 establishes requirements 
for Federal agencies to protect sensitive data.

	Public Law 100-235, The Computer Security Act of 1987, creates a means for establishing 
minimum acceptable security practices for systems processing sensitive information.

	Executive Order 12356 prescribes a uniform system for classifying, declassifying, and 
safeguarding national security information.

1.1.2	DEPARTMENT OF DEFENSE SECURITY POLICY

DODD 5200.28, Security Requirements for Automated Information Systems (AISs), is the 
overall computer security policy document for the DOD. The document identifies mandatory and 
minimum AIS security requirements. Each agency may issue its own supplementary instructions. 
For DOD agencies, these instructions fall within the scope of the DOD guidelines and add more 
specificity. Additional requirements may be necessary for selected systems, based on risk 
assessments.

Additional security documents are:

	Department of Defense 5220.22-M, Industrial Security Manual for Safeguarding 
Classified Information.

	Defense Intelligence Agency Manual (DIAM) 50-4, Security of Compartmented Computer 
Operations (U).

	Director of Central Intelligence Directive (DCID) 1/16, Security Policy for Uniform 
Protection of Intelligence Processed in Automated Information Systems and Networks (U).

	The Supplement to DCID 1/16, Security Manual for Uniform Protection of Intelligence 
Processed in Automated Information Systems and Networks (U).

	National Security Agency/Central Security Service (NSA/CSS) Manual 130-1, The NSA/
CSS Operational Computer Security Manual.

	Air Force Regulation (AFR) 205-16, Computer Security Policy.

	Army Regulation (AR) 380-19, Security: Information Systems Security.

	Chief of Naval Operations Instruction (OPNAVINST) 5239.1A, Automatic Data 
Processing Security Program.

1.1.3	SECURITY STANDARDS

The National Computer Security Center (NCSC) is responsible for establishing and 
maintaining technical standards and criteria for the evaluation of trusted computer systems. As part 
of this responsibility, the NCSC has developed the Trusted Computer System Evaluation Criteria 
(TCSEC), also known as the "Orange Book" after the color of its cover, which defines technical 
security criteria for evaluating general purpose AISs. [3] In 1985, the TCSEC became a DOD 
standard (DOD 5200.28-STD) and is mandatory for use by all DOD components. The TCSEC rates 
computer systems based on an evaluation of their security features and assurances. The Trusted 
Network Interpretation (TNI) interprets the TCSEC for networks and provides guidance for 
selecting and specifying other security services (e.g., communications integrity, denial of service, 
and transmission security). [4]

1.2	PURPOSE

The primary purpose of this guideline is to provide guidance to ISSOs, who are responsible 
for implementing and maintaining security in a system. The system may be a remote site linked to 
a network, a stand-alone AIS, or workstations interconnected via a local area network. Throughout 
this guideline, the term "site" will be used to refer to the AIS configuration that is the responsibility 
of the ISSO. The ISSO may be one or more individuals who have the responsibility to ensure the 
security of an AIS excluding, for example, guards, physical security personnel, law enforcement 
officials, and disaster recovery officials. This guideline also discusses the roles and responsibilities 
of other individuals who are responsible for security and their relationship to the ISSO, as defined 
in various DOD component regulations and standards.

This guideline provides general information and does not include requirements for specific 
agencies, branches, or commands. Therefore, the information included in this document should be 
considered as a baseline with more detailed security guidelines provided by each agency, branch, 
or command.

Finally, it is assumed that individuals who will be using this document have some background 
in security. This guideline presents some terms and definitions to provide a common framework 
for the information it presents; however, it does not provide a complete tutorial on security.

1.3	STRUCTURE OF THE DOCUMENT

Section 2 of this document identifies the operational environment. Section 3 presents the role 
and responsibilities of the ISSO and the environment in which the ISSO performs these tasks. 
Section 4 discusses the role and responsibilities of security personnel within an organization and 
the position of the ISSO. A bibliography and a reference list of security regulations, standards, and 
guidelines that provide additional information on system security are included following section 4. 
An acronym list and a glossary of computer security terms are included at the end of this document.

2.	OPERATIONAL ENVIRONMENT

The ISSO performs security tasks for a site that may support several different user 
communities. Therefore, the ISSO must understand the operational characteristics of the site. 
Documentation on the site configuration should be available and should, at a minimum, contain the 
following:

	Overall mission of the site.

	Overall floor layout.

	Hardware configuration at the site, identifying all the devices and the connections between 
devices and location, number, and connections of remote terminals and peripherals.

	Software at the site, including operating systems, database management systems, and 
major subsystems and applications.

	Type of information processed at the site (e.g., classified, sensitive unclassified, and 
intelligence).

	User organization and security clearances.

	Operating mode of the site (e.g., system high, dedicated, and multilevel secure).

	Interconnections to other systems/networks of users, e.g., the Automatic Digital Network 
(Autodin).

	Security personnel and associated responsibilities.

This documentation may be prepared jointly by the operations management and the ISSO. 
The following subsections provide additional information on the type of information processed and 
the operating mode of the site.

2.1	TYPE OF INFORMATION PROCESSED

The information that is stored, processed, or distributed at the site will be included in one of 
the following classification levels that designates the sensitivity of the data.

2.1.1	UNCLASSIFIED

Unclassified information is any information that need not be safeguarded against disclosure, 
but must be safeguarded against tampering, destruction, or loss due to record value, utility, 
replacement cost or susceptibility to fraud, waste, or abuse. [2] Life-critical and other types of 
critical process control data that are unclassified also must be protected.

2.1.2	SENSITIVE UNCLASSIFIED

The loss, misuse, or unauthorized access to, or modification of this information might 
adversely affect U.S. national interest, the conduct of DOD programs, or the privacy of DOD 
personnel. [2] Examples include financial, proprietary, and mission-sensitive data.

2.1.3	CONFIDENTIAL

The unauthorized disclosure of this information or material could reasonably be expected to 
cause damage to the national security. [5]

2.1.4	SECRET

The unauthorized disclosure of this information or material could reasonably be expected to 
cause serious damage to the national security. [5]

2.1.5	TOP SECRET

The unauthorized disclosure of this information or material could reasonably be expected to 
cause exceptionally grave damage to the national security. [5]

2.2	SECURITY MODE OF OPERATION

The Designated Approving Authority (DAA) accredits an AIS to operate in a specific security 
mode. The security mode selected reflects whether or not all users have the necessary clearance, 
formal access approval, and need-to-know for all information contained in the AIS.

Formal access approval is the documented approval by a data owner to allow access to a 
particular category of information. [2] The modes are defined below with the distinctions noted in 
italics for emphasis. The definitions are based on DODD 5200.28, except for compartmented 
security mode, which is based on DCID 1/16. Note that some terms that appear in Computer 
Security Requirements - Guidance for Applying the Department of Defense Trusted Computer 
System Evaluation Criteria in Specific Environments, CSC-STD-003-85, are no longer defined in 
DODD 5200.28. (Limited access mode and compartmented mode fall under the heading of 
partitioned mode. Controlled mode comes under the heading of multilevel security mode. In 
DODD 5200.28, partitioned mode is used in place of compartmented mode.) In addition, other 
modes of operation may be stipulated by the organization or agency that includes the site.

2.2.1	DEDICATED SECURITY MODE

An AIS operates in dedicated security mode when each user with direct or indirect individual 
access to the AIS, its peripherals, remote terminals, or remote hosts has the clearance or 
authorization, documented formal access approval, if required, and need-to-know for all 
information handled by the AIS. [2] An AIS operating in dedicated mode does not require any 
additional technical capability to control access to information. When in the dedicated security 
mode, the system is specifically and exclusively dedicated to and controlled for the processing of 
one particular type or classification of information, either for full-time operation or for a specified 
period of time. [6]

2.2.2	SYSTEM HIGH SECURITY MODE

System high security mode is a mode of operation wherein all users having access to the AIS 
possess a security clearance or authorization as well as documented formal access approval, but 
not necessarily a need-to-know, for all data handled by the AIS. [2] An AIS operating in system 
high security mode must have the technical capability to control access to information based on a 
user's need-to-know. Need-to-know may be specified using access control lists (ACLs) or non-
hierarchical schemes for categorizing information.

2.2.3	PARTITIONED SECURITY MODE

In partitioned security mode, all users have the clearance but not necessarily formal access 
approval and need-to-know for all information contained in the system. This means that some users 
may not have need-to-know and formal access approval for all data processed by the AIS. [2]

An AIS operating in partitioned mode must have the technical capability to control access to 
information based on need-to-know and the sensitivity level of the data in the system.

2.2.4	COMPARTMENTED SECURITY MODE

DCID 1/16 defines compartmented security mode wherein each user has a valid clearance for 
the most restricted intelligence information processed in the AIS. Each user also has formal access 
approval, a valid need-to-know, and a signed nondisclosure agreement for that intelligence 
information to which the user is to have access. [7]

2.2.5	MULTILEVEL SECURITY MODE

Multilevel security (MLS) mode is a mode of operation wherein not all users have a clearance 
or formal access approval for all data handled by the AIS. This mode of operation can 
accommodate the concurrent processing and storage of (a) two or more levels of classified data, or 
(b) one or more levels of classified data with unclassified data depending upon the constraints 
placed on the system by the DAA. [2] An AIS operating in multilevel mode must have the technical 
capability to control access to information based on need-to-know, formal access approval, and 
sensitivity level of the data in the system. (Note: Controlled mode is not separately defined in 
DODD 5200.28. It is included in multilevel mode.)

3.	ISSO AREAS OF RESPONSIBILITY

Within an organization, the ISSO may be one or more individuals who have the responsibility 
to ensure the security of an AlS. "ISSO" does not necessarily refer to the specific functions of a 
single individual. Also, additional responsibilities may be defined by the ISSO's specific 
organization. The administration of system security can be centralized or decentralized depending 
upon the needs of the organization. Where multiple data center locations are involved, the 
decentralized approach may be more appropriate. However, one focal point should coordinate all 
information security policy. Also, the responsibility for information security rests with all 
members of the organization and not just the security personnel.

The ISSO supports two different organizations: the user organization and the technical 
organization. The user organization is primarily concerned with providing operations and the 
technical organization focuses on protecting data. It is recommended that the ISSO not report to 
operational elements of the Al5 that must abide by the security requirements of the applicable 
directives, policies, etc. The objective is to provide a degree of independence for the ISSO. The 
ISSO shall report to a high level authority who is not the operational manager. Also, the rank or 
grade of the ISSO shall be commensurate with the assigned responsibilities.

3.1	ISSO TECHNICAL QUALIFICATIONS

The DAA, or a designee, ensures an ISSO is named for each AIS. This individual and the 
ISSO's management should ensure that the ISSO receives applicable training to carry out the 
duties. The ISSO position requires a solid technical background, good management skills, and the 
ability to deal well with people at all levels from top management to individual users. At a 
minimum, the ISSO should have the following qualifications:

	Two years of experience in a computer related field.

	One year of experience in computer security, or mandatory attendance at a computer 
security training course.

	Familiarization with the operating system of the AIS.

	A technical degree is desirable in computer science, mathematics, electrical engineering, 
or a related field.

3.2	OVERVIEW OF ISSO RESPONSIBILITIES

The ISSO acts for the Component Information System Security Manager (CISSM) to ensure 
compliance with AIS security procedures at the assigned site or installation. DODD 5200.28 
summarizes the duties of the ISSO as follows:

	Ensure that the AlS is operated, used, maintained, and disposed of in accordance with 
internal security policies and practices.

	Ensure the AIS is accredited if it processes classified information.

	Enforce security policies and safeguards on all personnel having access to the AIS for 
which the ISSO has responsibility.

	Ensure that users and system support personnel have the required security clearances, 
authorization and need-to-know; have been indoctrinated; and are familiar with internal 
security practices before access to the AIS is granted.

	Ensure that audit trails are reviewed periodically, (e.g., weekly or daily). Also, that audit 
records are archived for future reference, if required.

	Initiate protective or corrective measures if a security problem is discovered.

	Report security incidents in accordance with DOD 5200.1 -R and to the DAA when an AIS 
is compromised.

	Report the security status of the AIS, as required by the DAA.

	Evaluate known vulnerabilities to ascertain if additional safeguards are needed.

	Maintain a plan for site security improvements and progress towards meeting the 
accreditation.

3.3	ISSO SECURITY RESPONSIBILITIES

Command-specific duties of the ISSO have been well-defined in many regulations, directives, 
and documents, e.g., AFR 205-16, AR 380-19, and OPNAVINST 5239.1A. This guideline 
provides a more general discussion of ISSO responsibilities, which may be tailored to a particular 
environment. The remainder of section 3 details ISSO responsibilities. Some of these 
responsibilities are necessary to support the security duties as summarized above. The material is 
not presented in a specific order.

3.4	SECURITY REGULATIONS AND POLICIES

The ISSO shall be aware of the directives, regulations, policies, and guidelines that address 
the protection of classified information, as well as sensitive unclassified information. The overall 
security documents are discussed in section 1. Also, each command and agency may have 
additional requirements that provide more detailed guidance on protecting sensitive information. 
It may be necessary for the ISSO to prepare, or have prepared, a list of the applicable directives, 
regulations, etc., if one is not available.

Security Documentation. The ISSO participates in the development or revision of site-
specific security safeguards and local operating procedures that are based on the above regulations. 
The objective is to include the ISSO during the development and writing rather than only at the 
implementation phase. The overall site security document is the security plan. It contains the 
security procedures, instructions, operating plans, and guidance for each AIS at the site.

The ISSO also provides input to other security documents, for example, security incident 
reports, equipment/software inventories, operating instructions, technical vulnerabilities reports, 
and contingency plans.

Two documents that the ISSO should be familiar with, required for products with security 
features at the C1 level or above, are discussed below:

	The Trusted Facility Manual (TFM) details security functions and privileges. It is designed 
to support AIS administrators (e.g., the ISSO, the database administrator, and computer 
operations personnel). It addresses the configuration, administration, and operation of the 
AIS. It provides guidelines for the consistent and effective use of the protection features of 
the system. (Additional information is provided in the TCSEC.)

	The Security Features User's Guide (SFUG) assists the users of the AIS. It describes how 
to use the protection features of the AIS correctly to protect the information stored on the 
system. The SFUG discusses the features in the AIS that are available to users, as well as 
the responsibilities for system security that apply to users.

3.5	MISSION NEEDS

The ISSO shall understand the organization's mission needs, that is, the goals and objectives 
of the organization and the resources required to accomplish these goals. Requirements are 
specified by analyzing the organization's current capabilities, available resources, facilities, funds, 
and technology base, and by determining whether they are sufficient to fulfill the mission. If not, 
the mission needs should be evaluated and prioritized and a plan developed to address these needs. 
Because security requirements should be included in the mission needs and current assets 
assessment, it is important for the ISSO to become involved in the mission definition process.

3.6	PHYSICAL SECURITY REQUIREMENTS

In general, physical security addresses facility access and the protection of the structures and 
components that contain the AIS and network equipment. Physical security also addresses 
contingency plans and the maintenance and destruction of storage media and equipment. These 
physical safeguards must meet the minimum requirements established for the highest classification 
of data stored at the site. The ISSO in coordination with site security personnel is responsible for 
ensuring that physical safeguards are in place. Facility access and maintenance are further 
discussed in section 3.10. Contingency planning and declassification are discussed in sections 
3.6.1 and 3.6.2.

3.6.1	CONTINGENCY PLANS

The Information System Security Manager (ISSM) is responsible for the formulation, testing, 
and revision of site contingency plans because of the manager's accountability for ensuring 
continuity of operations. The contingency plans document emergency response, backup 
operations, and post-disaster recovery procedures. While the ISSM has overall responsibility for 
the plans, the ISSO provides technical contributions concerning the overall security plans to ensure 
the availability of critical resources and to facilitate system availability in an emergency situation. 
It is also important that all responsibilities under the plan are adequately documented, 
communicated, and tested.

3.6.2	DECLASSIFICATION AND DOWNGRADING OF DATA AND EQUIPMENT

Declassification is a procedure and an administrative action to remove the security 
classification of the subject media. Downgrading is a procedure and an administrative action to 
lower the security classification of the subject media. The procedural aspect of declassification is 
the actual purging of the media and removal of any labels denoting classification, possibly 
replacing them with labels denoting that the storage media is unclassified. The procedural aspect 
of downgrading is the actual purging of the media and removal of any labels denoting the previous 
classification, replacing them with labels denoting the new classification. The administrative 
aspect is realized through the submission to the appropriate authority of a decision memorandum 
to declassify or downgrade the storage media.

The ISSO must ensure that:

	Purging, declassification, and downgrading procedures are developed and implemented.

	Procedures are followed for purging, declassifying, downgrading, and destroying storage 
media.

	Procedures are followed for marking, handling, and disposing of the computer, its 
peripherals, and removable and nonremovable storage media.

	Any special software needed to overwrite the site-unique storage media is developed or 
acquired.

	Any special hardware, such as degaussers, is available.

3.7	ADMINISTRATIVE SECURITY PROCEDURES

Administrative security includes the preparation, distribution, and maintenance of plans, 
instructions, guidelines, and operating procedures regarding security of AISs. It is the 
responsibility of the ISSO to assist in the development of administrative procedures, if required, 
and to conduct periodic reviews to ensure compliance.

3.7.1	PERSONNEL SECURITY

One component of administrative security is personnel security. In general, it is the 
responsibility of the ISSO to:

	Ensure that all personnel and, when required, specified maintenance personnel who install, 
operate, maintain, or use the system, hold the proper security clearances and access 
authorizations.

	Ensure that all system users, including maintenance personnel, are educated by their 
respective security officer in applicable security requirements and responsibilities.

	Maintain a record of valid security clearances, physical access authorizations, and AIS 
access authorizations for personnel using the computer facility.

	Ensure that maintenance contractors who work on the system are supervised by an 
authorized knowledgeable person.

3.7.2	SECURITY INCIDENTS REPORTING

A security incident occurs whenever information is compromised, when there is a risk of 
compromise of information, when recurring or successful attempts to obtain unauthorized access 
to a system are detected, or where misuse of the system is suspected.

The ISSO creates a reporting mechanism, as part of the security incident reporting procedure, 
for users to keep the ISSO informed of security-relevant activity that they observe on the system. 
This reporting mechanism shall not use the AIS to report security-relevant activity about the AIS.

The mechanism, at a minimum, includes the following:

	Description of incident.

	Identification of the individual reporting the security incident.

	Identification of the loss, potential loss, access attempt, or misuse.

	Identification of the perpetrator (if possible).

	Notification of appropriate security and management personnel and civil authorities, if 
required.

	Reestablishment of protection, if needed.

	Restart of operations, if the system had been taken down to facilitate the investigation.

The ISSO performs the following in support of this task:

	Prepares procedures for monitoring and reacting to system security warning messages and 
reports.

	Develops, reviews, revises, and submits for approval to the DAA and technical supervisor, 
procedures for reporting, investigating, and resolving security incidents at the site.

	Immediately reports security incidents through the appropriate security and management 
channels (e.g., ISSM and Program Manager). The ISSO submits an analysis of the security 
incident to the appropriate authority for corrective and disciplinary actions.

	Performs an initial evaluation of security problems, and, if necessary, temporarily denies 
access to affected systems. The ISSO ensures that Terminal Area Security Officers 
(TASOs) evaluate, report, and document security problems and vulnerabilities at their 
respective remote terminal areas.

	Partially or completely suspends operations if any incident is detected that affects security 
of operations. This would include any system failure. (Note: this may be unrealistic if the 
system performs a critical operational mission. Alternative procedures may be required in 
this situation. The DAA must weigh the risk of a security incident against the potential 
damage in shutting down the system.)

	Ensures that all cases of actual or suspected compromise of classified passwords are 
investigated.

	Ensures that occurrences within the system that may affect the integrity and security of the 
data being processed are investigated. If the system malfunctions, it is important to account 
for the data.

	Assists the investigating officials in analyzing actual or suspected compromises of 
classified information.

3.7.3	TERMINATION PROCEDURES

The ISSO is responsible for performing the following tasks whenever any user's access is 
terminated. Prompt action is required, particularly if the termination or knowledge of the pending 
termination might provoke a user to retaliate.

	Removes the user from all access lists, both manual and automated.

	Removes the individual's account from all systems, including the user's password.

	Ensures that the individual has turned in all keys, tokens, or cards that allow access to the 
AIS.

	Ensures that combinations of any combination locks, associated with the AIS and its 
physical space, that the individual accessed are changed.

	Ensures that all remaining personnel using systems processing classified data change their 
passwords to prevent unauthorized access.

3.8	SECURITY TRAINING

Because personnel are an integral part of the security protection surrounding an AIS, they 
must understand the vulnerabilities, threats, and risks inherent with AIS usage. Therefore, 
computer security shall be included in briefings given to all new personnel. To reinforce this initial 
training and to introduce new concepts, periodic training and security awareness programs should 
be conducted. The ISSO shall continue training to keep current in security products and 
procedures. The ISSO is responsible for ensuring that:

	All personnel (including management) have computer security awareness training and 
have read applicable sections of the AIS security plan. This includes training in security 
procedures and the use of security products.

	All users are educated regarding password management (e.g., generating unique 
passwords, keeping passwords adequately protected, not sharing passwords, changing 
passwords on a regular basis, and generating different passwords for each system 
accessed).

	Users understand the importance of monitoring their successful and unsuccessful logins, if 
possible. If these do not correspond to the user's actual usage, the user should know the 
proper procedures for reporting the discrepancy.

The ISSO can keep users informed about security in many different ways. Some approaches 
follow:

	Periodically display messages on the AIS when the user logs on to the system.

	Develop and distribute security awareness posters to foster interest.

	Disseminate new security information about the system and issue reminder notices about 
protection procedures.

	Issue memos to notify users of changes.

	Provide "hands-on" demonstrations of AIS security features and procedures.

3.9	SECURITY CONFIGURATION MANAGEMENT

Configuration management controls changes to system software, firmware, hardware, and 
documentation throughout the life of the AIS. This includes the design, development, testing, 
distribution, and operation of modifications and enhancements to the existing system. The ISSO or 
other designated individual aware of the security issues shall be included in the configuration 
management process to ensure that implemented changes do not compromise security. It is 
particularly important for the ISSO to review and monitor proposed changes to the trusted 
computing base (TCB) as defined in the security architecture. Appropriate tests should be 
conducted to show that the TCB functions properly after changes are made to it. Configuration 
management tasks that are the responsibility of the ISSO are as follows:

	Maintain an inventory of security-relevant hardware and security-relevant software and 
their locations.

	Maintain documentation detailing the AIS hardware, firmware, and software configuration 
and all security features that protect it.

	Evaluate the effect on security of proposed centrally developed and distributed and site-
unique modifications to software and applications. Submit comments to appropriate 
personnel.

	Identify and analyze system malfunction. Prepare security incident reports.

	Assist in the development of system development notifications and system change 
proposals.

	Monitor DAA-approved site procedures for controlling changes to the current system.

	Ensure that any system connectivity is in response to a valid operational requirement.

	Ensure that continuing tests of the site security features are performed, and maintain 
documentation of the results.

	Coordinate AS security changes with the ISSM. Review all site configuration changes and 
system component changes or modifications to ensure that site security is not 
compromised.

	Review physical inventory reports of security-relevant AIS equipment. 

Hardware and Software Installation and Maintenance. The ISSO ensures that the 
design and development of new Systems or the maintenance or replacement of existing 
systems includes security features that will support certification and accreditation or 
reaccreditation. In support of this effort, informal reviews with the site certifiers can help 
identify potential problems, thus enabling potential security risks to be identified early. 
Before installing any new system release, the site shall complete sufficient testing to verify 
that the system meets the documented and approved security specifications and does not 
violate existing security policy. The ISSO shall, at a minimum, observe the testing of new 
releases. Specific ISSO tasks are:

	Ensure that all security-relevant development and planning activities are reviewed and 
approved.

	Participate in the acquisition planning process for proposed acquisitions to ensure that the 
site security policy has been considered. This applies to both the acquisition of new 
systems or the upgrade of existing systems.

	Ensure that security features are in place (by testing) to prevent applications programs from 
bypassing security features or from accessing sensitive areas of the system.

	Develop procedures to prevent the installation of software from unauthorized or 
questionable sources.

	Ensure that system support personnel know how to install and maintain security features.

3.10	ACCESS CONTROL

Access is considered from different perspectives: physical access to the facility and system 
(facility access), logical access to the system (identification and authentication), and logical access 
to the system's files and other objects (data access). Each of these is discussed separately below.

3.10.1	FACILITY ACCESS

Procedures shall be developed for controlling access to the site and the site's resources. In 
accordance with applicable security policy, system access shall be denied to any user, customer, or 
visitor who has not been granted specific authorization. General guidance for the ISSO follows:

	Establish procedures to ensure that only personnel who have a need-to-know have access 
to classified or sensitive but unclassified information.

	Establish procedures to ensure that only personnel who have the proper clearances and 
formal access approval are allowed physical access to any system containing classified 
information. All individuals who have routine access to the system should be properly 
cleared and have a valid operational requirement for access.

	Deny access to any user, customer, or visitor who is unauthorized or suspected of violating 
security procedures.

	Ensure all visitors are signed-in and escorted, if necessary. Visitors shall be under visual 
observation by an authorized person.

	Keep records of maintenance performed at the site.

	Establish and implement procedures to control AIS equipment coming into and going out 
of the site, including, for example, test devices, cable, and system disks.

	Develop and maintain a facility security plan that contains at least architectural drawings 
and building plans, floor plans, and inventories.

	Ensure that maintenance contractors who work on the system are supervised by an 
authorized knowledgeable person.

3.10.2	IDENTIFICATION AND AUTHENTICATlON (I&A)

The identification component of an I&A system consists of a set of unique user identifiers. 
Authentication involves verifying the identity of a user. If a user's identifier does not remain 
unique, a subsequent user may gain the access rights of a previous user on the system. General 
guidance to the ISSO follows:

	Ensure that the databases required to support the I&A function are accessible only by the 
ISSO.

	Obtain a list of all identifications (IDs) preset at the factory. Change or delete all user IDs 
and passwords that come with vendor software to prevent unauthorized access. Default 
passwords shall be checked and changed, as necessary, at system installation and 
modification, when the ISSO first assumes responsibility of the system, and after any 
maintenance to the system.

	Develop and administer a password management system that includes the generation of 
system passwords and development of procedures for addressing password loss or 
compromise.

	Ensure that only authorized persons execute system utility programs and routines that 
bypass security checks or controls.

	Maintain a site user list that contains the name, user ID, access level, and whether the user 
is to have operator or administrative privileges.

3.10.3	DATA ACCESS

The focus of data access procedures is to prevent disclosure of information to unauthorized 
individuals. General guidance for the ISSO follows:

	Ensure that the site-specific discretionary access control (DAC) policy is defined and 
implemented. The policy should define the standards and regulations that the ISSO must 
implement to ensure that data is disclosed only to authorized individuals.

	Control access to all functions that can affect the security or integrity of the system. Access 
of this type shall be kept to the absolute minimum number of personnel.

	Ensure that any required access control software subsystems or other security subsystems 
are installed and operated in a manner that supports the security policy of the AIS.

3.11	RISK MANAGEMENT

Risk management identifies, measures, and minimizes the effect of uncertain events on 
system resources. Risk management determines the value of the data, what protection already 
exists, and how much more protection the system needs. The process includes risk analysis, cost 
benefit analysis, safeguard selection and implementation, appropriate security tests, and systems 
review. Risk management is an ongoing process that will reaffirm the validity of previous analysis. 
The ISSO supports the risk management process by performing the following tasks:

	Assist in the development of the risk management plan.

	Perform a risk assessment and analysis by analyzing threats to the site and vulnerabilities 
of the site in relationship to the sensitivity of the information on the system. Document the 
results and prepare appropriate countermeasures. (This is expanded below.)

	Ensure a contingency plan is in place for continuity of operations in an emergency situation 
and that the developed plans are exercised.

	Ensure that approved countermeasures are implemented.

	Periodically review the risk assessment for new threats due to a changed configuration or 
changes in the operational environment and review contingency plans to ensure that they 
are still applicable.

	Ensure that security tests, risk analysis, TEMPEST tests, and other inspections are 
conducted as required. Maintain a file of working papers concerning security tests, risk 
analysis, and other facets of the risk management program.

	Maintain a file of all site security-related waivers.

The ISSO documents and reports computer security technical vulnerabilities detected in AISs, 
in accordance with DOD Instruction 5215.2. The report includes information regarding technical 
solutions or administrative procedures implemented to reduce the risk. Each ISSO administers the 
technical vulnerability reporting program and:

	Reports identified technical vulnerabilities. As a further way of sharing information about 
vulnerabilities, maintains contact with other system security officers and with other users 
of the same type of system.

	Assumes responsibility for recommending any necessary and feasible action to reduce 
risks presented by the vulnerabilities.

	Develops local procedures for reporting and documenting technical vulnerabilities, and 
ensures that all users and operators receive training for carrying-out the procedures.

	Ensures that vulnerability information is properly classified and protected.

3.12	AUDITS

The ISSO has the primary responsibility to conduct security audits for operational systems as 
well as for systems under development. Monitoring of variances in security procedures is also 
important and is best controlled by the ISSO. As part of variance monitoring, the ISSO reviews any 
relevant audit trail data from the system. Finally, the ISSO provides senior management with 
reports on the effectiveness of security policy, with identification of weaknesses and 
recommendations for improvements.

3.12.1	AUDIT TRAILS

The audit trail provides a record of system security-related activity and allows the ISSO to 
monitor activities on the system. To be an effective security tool, the audit trail should be able to 
monitor, for example, successful and unsuccessful access attempts, file accesses, type of 
transaction, and password changes. If manual audits are necessary, the ISSO shall document 
random checks made to verify that users are recording system usage. Audit trail files must be 
protected to prevent unauthorized changes or destruction.

3.12.2	AUDITING RESPONSIBILITIES

Appropriate audit trail data shall be reviewed by the ISSO. Besides the system audit trail, 
network audit reports can provide detailed information on network traffic and provide summary 
accounting information on each user ID, account, or process. The responsibilities of the ISSO 
follow:

	Review specifications for inclusion of audit trail reduction tools that will assist in audit trail 
analysis.

	Select security events to be audited. Ensure that the audit trail is reviewed and have the 
capability to audit every access to controlled system resources (e.g., very sensitive files). 
Archive audit data.

	Develop and implement audit and review procedures to ensure that all AIS functions are 
implemented in accordance with applicable policies and programs. Existing policies and 
programs usually establish the minimum amount of material that shall be audited.

	Conduct audits and maintain documentation on the results.

	Supervise review of security audit parameters. Develop, review, revise, submit for 
approval, and implement procedures for monitoring and reacting to security warning 
messages and reports.

	Conduct random checks to verify compliance with the security procedures and 
requirements of the site.

	Gather information from audit trails to create profiles of system users. Observe user 
patterns such as the terminal usually used, files accessed, normal hours of access, and 
permissions usually requested, to determine which actions are unusual and shall be 
investigated.

	Review user access reports generated by the audit trail, in compliance with policies and 
practices.

	Review audit trail reports for anomalies:

-	Look for multiple unsuccessful logon attempts. This could be an indication of an 
inexperienced user, a user who has recently changed passwords and forgotten the new 
one, or an attempted intrusion.

-	Look for an attempt by a user, who is already logged in at a terminal, to log in again 
to the same system from a second terminal. This could be caused by an inadvertent 
failure to log out, an intentional logon to both terminals, or an attempted intrusion.

-	Be alert to individuals logging in after normal hours. This may mean the user has a 
deadline to meet and is working overtime or that an intruder is attempting access.

-	Look for high numbers of unsuccessful file accesses. This could be prompted by the 
user' failure to remember file names or by an attempted intrusion.

-	Look for unexplained changes in system activity.

-	Look for covert channel activity.

3.13	CERTIFICATION AND ACCREDITATION

Certification is the technical evaluation of an AIS's security features, including non-AIS 
security features (e.g., administrative procedures and physical safeguards), against a specified set 
of security requirements. The objective is to determine how well the AIS design and 
implementation meet this pre-defined set of security requirements. Certification is performed as 
part of the accreditation process. Accreditation is the formal management decision made by the 
DAA to implement an AIS or network in a specific operational environment at an acceptable level 
of risk. The certification package specifies the following in support of accreditation:

	Security mode.

	Set of administrative, environmental, and technical security safeguards.

	Operational environment.

	Interconnections to other AIS or networks.

	Vulnerabilities as well as procedural and physical safeguards.

The ISSO is frequently responsible for the following list of tasks in preparation for 
accreditation of a particular AIS:

	Assist in preparing the accreditation material required by the DAA.

	Assist in the evaluation of the accreditation package.

	Assist in the site surveys.

	Prepare a statement to the DAA about the certification report. The report should include a 
description of the system and its mission; the results from the testing, document reviews, 
and hardware and software reviews; remaining system vulnerabilities; and any additional 
controls or environmental requirements that may be necessary.

	Ensure that the site maintains the system security baseline through audits.

	Notify the DAA or the DAA's representative of all configuration changes that may change 
the site's security baseline.

4.	SECURITY PERSONNEL ROLES

Although this guideline focuses on the role and responsibility of the ISSO, it is important to 
understand how the ISSO position relates to other positions that have some security responsibility 
within an organization. This section outlines these other positions with security responsibilities.

DOD regulations define security roles and responsibilities for personnel responsible for AIS 
security. Overall roles and responsibilities are similar across DOD, but are assigned different titles 
in each service/agency. Table 1 summarizes the titles and positions across the DOD components.

One of the roles not addressed in Table 1 or 2 is that of the Program Manager (PM). While 
this is not specifically a security function, the PM must be aware of the AIS security requirements. 
The PM should establish a computer security working group (CSWG) consisting of individuals 
from the program office, users, procurement specialists, consultants, local computer security 
organizations, and the developers. During the acquisition process, this group shall review and 
evaluate security-related documents and issues such as specifications, security test plans and 
procedures, and risk management plans and procedures. The following sections list responsibilities 
for each of the identified security roles. Depending on the size, geographical distribution, and 
complexity of the site, the role of the ISSM (Information System Security Manager)/NSM 
(Network Security Manager) may be filled by the same individual(s) as the lSSO/NSO (Network 
Security Officer).

Table 1

Service and Agency Security Personnel Titles



Level

Air Force1

Army1

Navy1

DIA

System Wide

MAJCOM2,3

MCSSM

MACOM2

ISSPM

COMNAVCOMTELCOM2

MDIC or SIO2

AIS Site

BCSSM

CFM4

CSSO



TASO

ISSM

ISSO





TASO

ADPSO

ADPSSO/ISSO

MSO

TASO



ISSO

Network Site

NM

NSM

NSO





NSO

NSO

NSO

1.	Not SCI (Sensitive Compartmented Information), SIOP-ESI (Single Integrated Operational Plan-Extremely 
Sensitive Information)

2.	DAA

3.	There many be multiple MAJCOMs at a base, each with one or more AIS sites

4.	There is only one BCSSO per base to which all CFMs provide information

ADPSO	ADP Security Officer

ADPSSO	ADP System Security Officer

BCSSM	Base Communications-Computer Systems Security Manager

BCSSO	Base Communications-Computer Systems Security Officer

CFM	Computer Facility Manager

COMNAVCOMTELCOM	Commander, Naval Computer and Telecommunications Command

CSSM	Communications-Computer System Security Manager

CSSO	Computer System Security Officer

DAA	Designated Approving Authority/Designated Accreditation Authority

ISSM	Information System Security Manager

ISSO	Information System Security Officer

ISSPM	Information System Security Program Manager

MACOM	Major Army Command

MAJCOM	Major Command (Air Force)

MCSSM	MAJCOM CSSM

MDIC	Military Department Intelligence Officer

MSO	Media Sanitation Officer

NM	Network Manager

NSM	Network Security Manager

NSO	Network Security Officer

SIO	Senior Intelligence Officer

SSM	System Security Manager

TASO	Terminal Area Security Officer

Table 2 presents a uniform set of security roles and titles that will be used throughout this guideline.

Table 2

Uniform Security Personnel Titles



LEVEL

STAFF POSITION

System Wide

(Not SCI, SIOP-ESI)

DAA

CISSM

AIS Site

ISSM

ISSO

TASO

Network Site

NSM

NSO



CISSM	Component Information System Security Manager	

DAA	Designated Approving Authority

ISSM	Information System Security Manager

ISSO	Information System Security Officer

NSM	Network Security Manager

NSO	Network Security Officer

SCI	Sensitive Compartmented Information

SIOP-ESI	Single Integrated Operational Plan Extremely Sensitive 
Information

TASO	Terminal Area Security Officer

4.1	DESIGNATED APPROVING AUTHORITY (DAA)

The DAA grants final approval to operate an AIS or network in a specified security mode. [2] 
Before accrediting a site, the DAA reviews the accreditation documentation and confirms that the 
residual risk is within acceptable limits. The DAA also verifies that each AIS complies with the 
AIS security requirements, as reported by the ISSOs. Specific security responsibilities are as 
follows:

	Establish, administer, and coordinate security for systems that agency, service, or 
command personnel or contractors operate. Assist the PM in defining system security 
requirements for acquisitions.

	Appoint the individuals who will directly report to the DAA.

	Approve the classification level that is required for applications that are implemented in a 
network environment. Also, approve additional security services that are necessary (e.g., 
encryption and non-repudiation) to interconnect to external systems.

	Review the accreditation plan and sign the accreditation statement for the network and each 
AIS and define the criticality and sensitivity levels of each AIS.

	Review the documentation to ensure that each AIS supports the security requirements as 
defined in the AIS and network security programs.

4.2	COMPONENT INFORMATION SYSTEM SECURITY MANAGER (CISSM)

The CISSM is the focal point for policy and guidance in AIS and network security matters 
and reports to and supports the DAA. The CISSM administers both the AIS and network security 
programs within the component (defined as the Office of the Secretary of Defense, the military 
departments and the military services within those departments, the Joint Chiefs of Staff, the Joint 
Staff, the Unified and Specified Commands, the Defense agencies, the DOD field activities, and 
other such offices, agencies, activities, and commands as may be established by law, by the 
President, or by the Secretary of Defense that process data on AISs). [2] Additionally, the CISSM 
is responsible for subcomponents such as the MAJCOM, MACOM, or COMNAVCOMTELCOM, 
which are identified in Table 1. The CISSM, therefore, may be responsible for multiple AISs. 
Security responsibilities should include:

	Develop and administer AIS and network security programs that implement policy and 
regulations and are consistent with the accreditation plan. The network program shall 
define intrasystem and intersystem connectivity.

	Establish a risk management program for the entire AIS life cycle. This includes addressing 
network-wide security and problems associated with interconnecting to external systems.

	Identify the DAA for each unclassified system and each classified system.

	Identify each system in the certification and accreditation plan or in the system security 
plan.

	Advise the DAA about the use of specific security mechanisms.

	Provide periodic briefings to the component management and to the DAA.

	Report security vulnerabilities, maintain a record of security-related incidents, and report 
serious and unresolved violations to the DAA.

	Administer a security and training awareness program.

	Oversee maintenance of accreditation documentation.

	Provide for overall key distribution and encryption management.

	Enforce, through policy, compliance with component computer security program.

4.3	INFORMATION SYSTEM SECURITY MANAGER (ISSM)

The ISSM reports to the CISSM and implements the overall security program approved by 
the DAA. The ISSM focuses on AIS security. There may be multiple ISSMs. The ISSM should not 
participate in the day-to-day operation of the AIS.

Specific security responsibilities are:

	Ensure that the AS security program requirements are met, including defining the security 
mode, specific security requirements, protocols, and standards. Develop applicable AIS 
security procedures.

	Implement the risk management program defined by the CISSM. Verify that the risk 
assessment is performed and that threats and vulnerabilities are reviewed to evaluate risks 
properly.

	Verify that appropriate security tests are conducted and that the results are documented.

	Review the accreditation plan and the reaccreditation activities, develop a schedule for the 
reaccreditation tasks, and initiate recertification and reaccreditation tasks under the 
direction of the DAA.

	Assist in site configuration management by reviewing proposed system changes and 
reviewing implemented system modifications for adverse security impact.

	Ensure that AIS security is included in all the contingency plans.

	Provide the DAA with the certification package to show that the AIS satisfies the security 
specifications for the data it processes, stores, or transmits. Document and maintain the 
evidence contained in the certification package.

	Monitor AIS personnel security procedures to ensure that they are being followed; 
coordinate and monitor initial and follow-up security training for AS personnel.

	Maintain a current AIS security plan.

4.4	NETWORK SECURITY MANAGER (NSM)

The NSM is responsible for the overall security operation of the network and is the focal point 
for policy, guidance, and assistance in network security matters. In addition, the NSM ensures that 
the network complies with the requirements for interconnecting to external systems. The NSM re-
ports to the CISSM and shall not participate in the day-to-day operation of the network. The tasks 
of the NSM are comparable to those of the ISSM. The security responsibilities are listed in the 
same order as those for the ISSM, for ease of comparison, with differences indicated by italics:

	Ensure that an NSO is appointed for each network.

	Ensure that the AIS security program requirements are met, including defining the security 
mode, specific security requirements, protocols, and standards. Develop applicable 
network security procedures.

	Implement the risk management program defined by the CISSM. Verify that the risk 
assessment is performed and that threats and vulnerabilities are reviewed to evaluate risks 
properly.

	Verify that appropriate security tests are conducted and that the results are documented.

	Review the accreditation plan and the reaccreditation activities, develop a schedule for the 
reaccreditation tasks, and initiate recertification and reaccreditation tasks under the 
direction of the DAA.

	Assist in site configuration management by reviewing proposed system changes and 
reviewing implemented system modifications for adverse system impact.

	Ensure that network security is included in all the contingency plans.

	Provide the DAA with the certification package to show that the network satisfies the 
security specifications for the data it processes, stores, or transmits. Document and 
maintain the evidence contained in the certification package.

	Provide the DAA with written certification that the satisfies the security specifications for 
the data it processes, stores, or transmits. Ensure that the documentation to support the 
certification is developed and maintained.

	Monitor implementation of AIS personnel security procedures to ensure that they are being 
followed; coordinate and monitor initial and follow-up security training for AIS personnel.

	Maintain a current AIS security plan.

	Manage routing control for security within the network (specify links or subnetworks that 
are considered to be trusted based on specific criteria).

4.5	INFORMATION SYSTEM SECURITY OFFICER (ISSO)

The ISSO acts for the CISSM to ensure compliance with AIS security procedures at the 
operational site or installation. Depending on the size and complexity of the AIS, the ISSO also 
may function as the ISSM and NSO. The duties of the ISSO are detailed in section 3.

4.6	NETWORK SECURITY OFFICER (NSO)

The NSO implements the network security program and acts as the point of contact for all 
network security matters. The responsibilities of the NSO are similar to those of the ISSO, with the 
NSO concentrating on network security and the ISSO concentrating on AIS security. The security 
responsibilities of the NSO are:

	Obtain written approval from the DAA to process classified or sensitive unclassified 
information on the network.

	Maintain the security processing specifications for the network.

	Ensure that standard security procedures and measures that support the security of the 
entire network are developed and implemented. Conduct periodic reviews to ensure 
compliance with network security procedures.

	Ensure that network security is included in all the contingency plans and that the 
contingency plans are tested.

	Maintain the site-specific portion of the accreditation documentation.

	Ensure that physical measures to protect the facility are in effect and that measures to 
protect mission-essential, sensitive data processing activities are implemented. Maintain 
liaison with organizations that are responsible for physical security, e.g., military police, 
fire control officials, base power plant officials, and emergency services.

	Review network configuration changes and network computer changes or modifications to 
ensure that network security is not degraded (including interfaces to separately accredited 
AISs). Ensure that network components (i.e., hardware, software, and firmware) are 
included in the configuration management program.

	Select security events that are to be audited or remotely collected; establish procedures for 
collecting the audit information; and review audit reports.

	Verify security clearances and access approval for personnel using the network.

	Coordinate and monitor initial and periodic security training for network personnel. Verify 
that all users receive network security training before being granted access to the network.

	Provide users with plans, instructions, guidance, and standard operating procedures 
regarding network operations. Conduct periodic reviews to ensure compliance.

	Verify that personnel security procedures applicable to the operation of the computer 
facility are followed.

	Report physical, personnel, and AIS security violations to the NSM. Report system failures 
that could lead to unauthorized disclosure.

	Review reported security problems and inform the NSM of security difficulties. Ensure 
that TASOs evaluate, document, and report security problems and vulnerabilities at their 
respective sites.

	Recommend partial or complete suspension of operations if any incident is detected that 
may affect security of the operation.

	Monitor the system recovery processes to assure that security features are correctly 
restored.

	Maintain guidelines that ensure that the physical, administrative, and personnel security 
procedures are followed.

4.7	TERMINAL AREA SECURITY OFFICER (TASO)

The TASO reports to the ISSO and is responsible for security procedures in an assigned 
remote terminal area. System access from the TASO's assigned remote terminals will not be 
allowed without authorization from the cognizant security officer. The TASO has the following 
security responsibilities:

	Ensure that there are written instructions specifying security requirements and operational 
procedures for each terminal area.

	Ensure access to a terminal is only to users with the need-to-know, clearance, and access 
approval for data that may be accessed from that terminal.

	Perform an initial evaluation of security problems in the assigned terminal area(s) and 
notify the ISSO of all security violations and any practices that may compromise system 
security.

	Verify that the physical security controls are in place and operational, for example, 
physically protecting the network interfaces (hardware connections).

	Collect and review selected remote facility audit records, document any reported problems, 
and forward them to the ISSO.

	Participate in security training and awareness.

	Ensure that the equipment custodian has all the component serial numbers written down 
and stored in a secure place.

4.8	SECURITY RESPONSIBILITIES OF OTHER SITE PERSONNEL

Because the overall security of a site is subject to the cooperation of everyone involved in the 
system, the discussion of roles and responsibilities would not be complete without mentioning the 
system administrator, the computer facility personnel, the data administrator, the maintenance 
personnel, and the users. Everyone is responsible for knowing the security procedures and 
mechanisms that are in effect for a particular system, for following all procedures applicable to 
security, and for reporting potential security incidents. In addition, specific responsibilities for 
other individuals are listed below.

The data administrator and classifier shall:

	Coordinate with the ISSO on information security requirements and with the NSO for 
network security requirements.

	Establish or confirm the overall security classification of the applicable resources and 
establish restrictions or special conditions for the use of the data.

	Periodically review the data to verify that the security classification is correct. Recommend 
downgrading data, if applicable.

	Authorize individual or group access to specific resources.

	Participate in the development of a formal need-to-know policy.

The users shall:

	Use the system only for authorized purposes and in accordance with security procedures 
and guidelines.

	Maintain individual accountability (e.g., do not share passwords).

	Protect classified and other sensitive material.

4.9	ASSIGNMENT OF SECURITY RESPONSIBILITIES

Table 3 presents a sample chart for identifying the roles and responsibilities of the various 
individuals who have security tasks. The primary goal is to identify all the tasks and ensure that at 
least one individual is assigned to perform each task.

Table 3

Function Matrix

Function

DAA

CISSM

ISSM

NSM

ISSO

NSO

TASO

Overall Security

PR

IM

IM

IM

IM

IM

IM

Accreditation Process

PR

IM

IM

IM

IN

IN

Recertification and 
Reaccreditation

PR

IM

IM

IM

IN

IN

AIS Security Program

PR

IM

IM

IM

IM

Network Security Program

PR

IM

IM

IM

Network Access

PR

PR

VE

DO, VE

SecurityThreats/
Vulnerabilities

PR

DO

DO

DO

IN, DO

DO, IN

DO

Security Regulations and 
Policies

IM

IM

IM

IM

IM

IM

IM

Security Documentation

VE

DO

DO

DO

IN

IN

IN

Risk Management Program

PR

IM

IM

IM, IN

IM, IN

Security Training and 
Awareness Program

PR

VE

VE

IM,VE

IM,VE

IM

Security Violations

DO

DO

DO

DO

DO

DO

Security Configuration 
Management

VE

IM

IM

IM

IM

AIS Security Procedures

 PR

IM, VE

IM, VE

IM, VE

Contingency Plans

PR, VE

PR, VE

IM, IN

IM, IN

 IM

Network Security 
Procedures

PR

IM,VE

Audit

PR

PR

PR,DO

Access Control

IM

IM

VE

Physical Security

VE

VE

VE

Declassification and  
Downgrading

VE



PR:	has primary responsibility

IM:	implements enforces task or program

DO:	prepares documentation and submits to appropriate authority, if applicable

VE:	verifies compliance or performance of activities

IN:	assists in the preparation of reports, plans, procedures, etc.

BIBLIOGRAPHY

This bibliography includes documents that may be useful to the ISSO. Included are directives, 
regulations, manuals, circulars, etc. Cited references are also included. This list is not intended to 
be comprehensive; that is, additional readings may apply to a particular organization and system, 
and the ISSO should identify all the relevant security documents.

Computer Security Act of 1987, Public Law 100-235, 101 STAT. 1724, 8 January 1988.

Defense Intelligence Agency, Physical Security Standards for Construction of Sensitive 
Compartmented Information Facilities, Defense Intelligence Agency (DIA) Manual 50-3, 
February 1990.

Defense Intelligence Agency, Security of Compartmented Computer Operations (U), DIA Manual 
50-4, CONFIDENTIAL, 1980.

Defense Intelligence Agency, Security Requirements for Automatic Data Processing (ADP) 
Systems, DlA Regulation 50-23, 14 March 1979.

Defense Intelligence Agency, Sensitive Compartmented Information Contractor Administrative 
Security, DlA Manual 50-5, FOR OFFICIAL USE ONLY (FOUO), VoI. 1,10 May 1983.

Department of the Air Force, Computer Security Policy, AF Regulation 205-16, FOUO, 28 April 
1989.

Department of the Army, Security: Information Systems Security, Army Regulation No. 380-19,4 
September 1990.

Department of Defense, Automated Data Processing Security Manual - Techniques and 
Procedures for Implementing, Deactivating, Testing, and Evaluating, Department of 
Defense (DOD) 5200.28-M, 1 January 1973 with change pages in June 1979 (now under 
revision).

Department of Defense, Communications Security (COMSEC) (U), Department of Defense 
Directive (DODD) C-5200.5, CONFIDENTIAL, 21 April 1990.

Department of Defense Computer Security Center, Computer Security Requirements - Guidance 
for Applying the Department of Defense Trusted Computer System Evaluation Criteria in 
Specific Environments, CSC-STD-003-85, 25 June 1985.

Department of Defense Computer Security Center, Password Management Guideline, CSC-STD-
002-85, 12 April 1985.

Department of Defense Computer Security Center, Technical Rationale Behind CSC-STD-003-85: 
Computer Security Requirements - Guidance for Applying the Department of Defense 
Trusted Computer System Evaluation Criteria in Specific Environments, CSC-STD-004-85, 
25 June 1985.

Department of Defense, Computer Security Technical Vulnerability Reporting Program 
(CSTVRP), DOD Instruction 5215.2,2 September 1986.

Department of Defense, Control of Compromising Emanations (U), DODD S-5200.19, SECRET, 
23 February 1990.

Department of Defense, DOD Information Security Program, DODD 5200.1, 7June1982.

Department of Defense, DOD Personnel Security Program, DODD 5200.2, 20 December 1979.

Department of Defense, Industrial Security Manual for Safeguarding Classified Information, 
DOD 5220.22-M, 3 January 1991.

Department of Defense, Industrial Security Program, DODD 5220.22, 1 November 1986.

Department of Defense, Industrial Security Regulation, DOD Regulation 5220.22-R, December 
1985.

Department of Defense, Information Security Program Regulation, DOD Regulation 5200.1-R, 
June 1986.

Department of Defense, Information Security Program Regulation, DOD 5200.1 -R/AFR 205-1, 
April 1987.

Department of Defense, Security Requirements for Automated Information Systems (AISs), DODD 
5200.28,21 March 1988.

Department of Defense, Trusted Computer System Evaluation Criteria, DOD 5200.28-STD, 
`December 1985.

Department of the Navy, Department of the Navy Automatic Data Processing Security Program, 
Chief of Naval Operations Instruction (OPNAVlNST) 5239.1A with change 1,3 August 
1982.

Department of the Navy, Department of the Navy Automated Information Systems (AIS) Security 
Program, SECNAVINST 5239.2,15 November 1989.

Department of the Navy Sensitive Compartmented Information (SCl)/lntelligence, Automated 
Information System (AIS) Security Program, NAVlNTCOMlNST 5239.3,23 July 1990.

Director of Central Intelligence, Security Manual for the Uniform Protection of Intelligence 
Processed in Automated Information Systems and Networks (U), Supplement to Director of 
Central Intelligence Directive (DCID) 1/16 (U), SECRET, 19 July 1988.

Director of Central Intelligence, Security Policy for Uniform Protection of Intelligence Processed 
in Automated Information Systems and Networks (U), Director of Central Intelligence 
Directive (DClD) 1/16, SECRET, 19 July 1988.

Executive Order, National Security Information, Executive Order 12356, 2 April 1982.

Ferdman, Mauro and Harriet G. Goldman and John A. Gunter, "Proposed Management Plan for 
Computer Security Certification of Air Force Systems," MTR-1 0774, The MlTRE 
Corporation, Bedford, MA, November 1989.

Headquarters Department of the Air Force, Information Systems: Information Systems Security, 
AFR 700-10,15 March 1985.

Joint Chiefs of Staff, Safeguarding the Single Integrated Operational Plan (SIOP) (U), 
Memorandum MJCS 75-87, SECRET, 20 May 1987.

Joint Chiefs of Staff, Security Policy for the WWMCCS Intercomputer Network, JCS Pub. 6-03.7, 
April 1988.

National Computer Security Center (NCSC), Computer Viruses: Prevention, Detection, and 
Treatment, C1 -Technical Report-001,12 March 1990.

National Computer Security Center (NCSC), Glossary of Computer Security Terms, NCSC-TG-
004, 21 October 1988.

National Computer Security Center, A Guide to Understanding Data Remanence in Automated 
Information Systems, NCSC-TG-025, September 1991.

National Computer Security Center, A Guide to Understanding Trusted Facility Management, 
NCSC-TG-01 5, 18 October 1989.

National Computer Security Center, Trusted Network Interpretation Environments Guideline, 
NCSC-TG-01 1, 1 August 1990.

National Computer Security Center, Trusted Network Interpretation of the Trusted Computer 
System Evaluation Criteria, NCSC-TG-005, July 1987.

National Institute of Standards and Technology, United States Department of Commerce, 
Computer Data Authentication, Federal Information Processing System Publication (FIP5 
PUB) 113,30 May 1985.

National Institute of Standards and Technology, United States Department of Commerce, Glossary 
for Computer Systems Security, FIPS PUB 39, February 1976.

National Institute of Standards and Technology, United States Department of Commerce, 
Guideline for Automatic Data Processing Risk Analysis, FIPS PUB 65, August 1979.

National Institute of Standards and Technology, United States Department of Commerce, 
Guideline for Computer Security Certification and Accreditation, FlPS PUB 102,27 
September 1983. 

National Institute of Standards and Technology, United States Department of Commerce, 
Guidelines for ADP (Automatic Data Processing) Contingency Planning, FlPS PUB 87, 27 
March 1981.

National Institute of Standards and Technology, United States Department of Commerce, 
Guidelines for Security of Computer Applications, FlPS PUB 73, 30 June 1980.

National Institute of Standards and Technology, United States Department of Commerce, 
Overview of Computer Security Certification and Accreditation, Special Publication (SPEC 
PUB) 500-109, April 1984.

National Institute of Standards and Technology, United States Department of Commerce, Security 
of Personal Computer Systems: A Management Guide, SPEC PUB 500-120, January 1985.

National Institute of Standards and Technology, United States Department of Commerce, 
Technology Assessment: Methods for Measuring the Level of Computer Security, SPEC 
PUB 500-133, October 1985.

National Security Agency/Central Security Service (NSA/CSS), The NSA/CSS Operational 
Computer Security Manual, NSA/CSS Manual 130-1, FOUO, l7October 1990.

National Security Agency/Central Security Service, Security for Automated Information Systems 
and Networks, NSA-CSS Directive 10-27, 4 January 1990.

National Security Agency, Information System Security Products and Services Catalogue, 
quarterly updates. The catalogue contains the following:

Cryptographic Products List

Endorsed Data Encryption Standard (DES) Products List

Protected Services List

Evaluated Products List

U.S. Government Preferred Products List

Degausser Products List

National Telecommunications and Information Systems Security Committee, Advisory 
Memorandum on Office Automation Security Guideline, National Telecommunications and 
Information Systems Security Advisory Memorandum (NTISSAM) COMPUSECN -87, 16 
January 1987.

National Telecommunications and Information Systems Security Committee, TEMPEST 
Countermeasures for Facilities (U), National Telecommunications and Information 
Systems Security Instruction (NTISSI) 7000, SECRET, l7 October 1988.

Office of Management and Budget (OMB), Internal Control Systems, OMB Circular No. A-123, 
1983.

Office of Management and Budget, Management of Federal Information Resources, OMB 
Circular No. A-I 30, December 1985.

Office of the President, National Policy for the Security of National Security Telecommunication 
and Information Systems (U), National Security Directive (NSD) 42, CONFIDENTIAL, 5 
July 1990.

Office of the President, National Policy on Telecommunications and Automated Information 
Systems Security, National Security Decision Directive (NSDD) 145, 17 September 1984.

Office of the Secretary of Defense, Automated Information System Security, Memorandum for the 
Members of the Military Departments, Chairman of the Joint Chiefs of Staff, Under 
Secretaries of Defense, General Counsel, Inspector General, Assistants to the Secretary of 
Defense, and Directors of the Defense Agencies, 1985.

REFERENCES

1.	National Computer Security Center (NCSC), Glossary of Computer Security Terms, NCSC-
TG-004, Version-I, 21 October 1988.

2.	Department of Defense (DOD), Security Requirements for Automated Information Systems 
(AISs), DOD Directive 5200.28, 21 March 1988.

3.	Department of Defense, Department of Defense Trusted Computer System Evaluation 
Criteria, DOD 5200.28-STD, 15 August 1983.

4.	National Computer Security Center, Trusted Network Interpretation of the Trusted Computer 
System Evaluation Criteria, NCSC-TG-005, July 1987.

5.	Department of Defense, Information Security Program Regulation, DOD 5200.1 -R, June 
1986.

6.	Department of Defense Computer Security Center, Computer Security Requirements - 
Guidance for Applying the Department of Defense Trusted Computer System Evaluation 
Criteria in Specific Environments, CSC-STD-003-85, 25 June 1985.

7.	Director of Central Intelligence, Security Policy for Uniform Protection of Intelligence 
Processed in Automated Information Systems and Networks (U), DClD 1/16, SECRET, 19 
July 1988.

ACRONYMS

ADP	Automatic Data Processing

ADPSO	ADP Security Officer

ADPSSO	ADP System Security Officer

AFR	Air Force Regulation

AS	Automated Information System

AR	Army Regulation

BCSSM	Base Communications-Computer Systems Security Manager

BCSSO	Base Communications-Computer Systems Security Officer

CFM	Computer Facility Manager

CISSM	Component Information System Security Manager

COMNAVCOMTELCOM	Commander, Naval Computer and Telecommunications Command

COMPUSEC	Computer Security

COMSEC	Communications Security

COTS	Commercial-Off-The-Shelf

CSSM	Communications-Computer System Security Manager

CSSO	Computer System Security Officer

CSTVRP	Computer Security Technical Vulnerability Reporting Program

CSWG	Computer Security Working Group

DAA	Designated Approving Authority/

	Designated Accreditation Authority

DAC	Discretionary Access Control

DCID	Director of Central Intelligence Directive

DES	Data Encryption Standard

DIA	Defense Intelligence Agency

DIAM	Defense Intelligence Agency Manual

DOD	Department of Defense

DODD	Department of Defense Directive

EO	Executive Order

EPL	Evaluated Products List

FIPS PUB	Federal Information Processing System Publication

FOIA	Freedom of Information Act

I&A	Identification and Authentication

ISSM	Information System Security Manager

ISSO	Information System Security Officer

ISSPM	Information System Security Program Manager

MAC	Mandatory Access Control

MACOM	Major Army Command

MAJCOM	Major Command (Air Force)

MCSSM	MAJCOM CSSM

MDIC	Military Department Intelligence Officer

MLS	Multilevel Security

MSO	Media Sanitation Officer

N	Not Classified but Sensitive

NACSI	National Communications Security Instruction

NCSC	National Computer Security Center

NM	Network Manager

NSA	National Security Agency

NSD	National Security Directive

NSDD	National Security Decision Directive

NSM	Network Security Manager

NSO	Network Security Officer

NSTISSAM	National Security Telecommunications and Information Systems 
Security Advisory Memorandum

NSTISSD	National Security Telecommunications and Information Systems 
Security Directive

NSTISSI	National Security Telecommunications and Information Systems 
Security Instruction

NSTISSP	National Security Telecommunications and Information Systems 
Security Policy

NTCB	Network Trusted Computing Base

NTISSAM	National Telecommunications and Information Systems Security 
Advisory Memorandum

NTISSD	National Telecommunications and Information Systems Security 
Directive

NTISSI	National Telecommunications and Information Systems Security 
Instruction

NTISSP	National Telecommunications and Information Systems Security 
Policy

OMB	Office of Management and Budget

OPNAVINST	Chief of Naval Operations Instruction

PM	Program Manager

RI	Risk Index

SAPI	Special Access Program for Intelligence

SCI	Sensitive Compartmented Information

SFUG	Security Features User's Guide

SIO	Senior Intelligence Officer

SIOP-ESl	Single Integrated Operational Plan-Extremely Sensitive Information

SPEC PUB	Special Publication

SPM	Security Program Manager

SSM	System Security Manager

TASO	Terminal Area Security Officer

TCB	Trusted Computing Base

TCSEC	Trusted Computer System Evaluation Criteria

TEMPEST	(Not an acronym)

TFM	Trusted Facility Manual

TNI	Trusted Network Interpretation

TNIEG	Trusted Network Interpretation Environments Guideline

WWMCCS	Worldwide Military Command and Control System

GLOSSARY

After each definition, the source is listed.

Access. A specific type of interaction between a subject (i.e., person, process, or input device) and 
an object (i.e., an AIS resource such as a record, file, program, or output device) that results in the 
flow of information from one to the other. Also, the ability and opportunity to obtain knowledge 
of classified, sensitive unclassified, or unclassified information. (DODD 5200.28)

Accountability. The property that enables activities on an AIS to be traced to individuals who may 
then be held responsible for their actions. (DODD 5200.28; AFR 205-16)

Accreditation. A formal declaration by the DAA that the AIS is approved to operate in a particular 
security mode using a prescribed set of safeguards. Accreditation is the official management 
authorization for operation of an AIS and is based on the certification process as well as other 
management considerations. (DODD 5200.28)

Administrative Security. The management constraints and supplemental controls established to 
provide an acceptable level of protection for data. Synonymous with procedural security. (NCSC-
TG-004-88)

Audit Trail. A chronological record of system activities that is sufficient to enable the 
reconstruction, reviewing, and examination of the sequence of environments and activities 
surrounding or leading to an operation, a procedure, or an event in a transaction from its inception 
to final results. (DODD 5200.28; FlPS PUB 39)

Authenticate. To establish the validity of a claimed identity. (DOD 5200.28-STD; JCS PUB 6-
03.7)

Authorization. Granting the right of access to a user, a program, or a process. (FlPS PUB 39)

Automated Information System (AIS). An assembly of computer hardware, firmware, and 
software configured to collect, create, communicate, compute, disseminate, process, store, and/or 
control data or information. (DODD 5200.28; DClD 1/16)

Certification. The technical evaluation, made as part of and in support of the accreditation process, 
that establishes the extent to which a particular computer system or network design and 
implementation meet a pre-specified set of security requirements. (AR 380-19; DODD 5200.28)

Classified Information. Information or material that is (a) owned by, produced for or by, or under 
the control of the U.S. Government; and (b) determined under Executive Order 12356, or prior 
order, DOD 5200.1 -R, to require protection against unauthorized disclosure; and (c) so designated. 
(DODD 5200.28)

Closed Security Environment. An environment that includes those systems in which both of the 
following conditions hold true:

a.	Application developers (including maintainers) have sufficient clearances and 
authorizations to provide an acceptable presumption that they have not introduced malicious 
logic. Sufficient clearance is defined as follows: where the maximum classification of data to 
be processed is Confidential or below, developers are cleared and authorized to the same level 
as the most sensitive data; where the maximum classification of data to be processed is Secret 
or above, developers have at least a Secret clearance.

b.	Configuration control provides sufficient assurance that applications are protected 
against the introduction of malicious logic prior to and during operation of system 
applications. (CSC-STD-003-85; CSC-STD-004-85)

Communications Security (COMSEC). The protection that insures the authenticity of 
telecommunications and which results from the application of measures taken to deny 
unauthorized persons information of value which might be derived from the acquisition of 
telecommunications. (FlPS PUB 39)

Compartmented Mode. An AIS is operating in compartmented mode when each user with direct 
or indirect access to the AIS, its peripherals, remote terminals, or remote hosts, has all of the 
following:

a.	A valid personnel clearance for the most restricted information processed in the AIS.

b.	Formal access approval for, and has signed nondisclosure agreements for that 
information to which he/she is to have access.

c.	A valid need-to-know for that information to which he-she is to have access. (NCSC-TG-
004-88)

Compromising Emanations. Unintentional data related or intelligence-bearing signals which, if 
intercepted and analyzed, disclose the classified information transmission received, handled or 
otherwise processed by any information processing equipment. (AR 380-19; NCSC-TG-004-88; 
AFR 205-16)

Controlled Mode. The mode of operation that is a type of multilevel security mode in which a 
more limited amount of trust is placed in the hardware/software base of the system, with resultant 
restrictions on the classification levels and clearance levels that may be supported. (CSC-STD-
003-85)

Countermeasure. Any action, device, procedure, technique or other measure that reduces the 
vulnerability of or threat to a system. (NCSC-TG-004-88)

Covert Channel. A communications channel that allows a process to transfer information in a 
manner that violates the system's security policy. (DOD 5200.28-STD; AFR 205-16)

Data. A representation of facts, concepts, information, or instructions suitable for communication, 
interpretation or processing by humans or by an AIS. (DODD 5200.28)

Data Owner. The authority, individual, or organization who has original responsibility for the data 
by statute, executive order, or directive. (DODD 5200.28)

Declassification. An administrative decision or procedure to remove or reduce the security 
classification of the subject media. (NCSC-TG-004-88)

Dedicated Security Mode. A mode of operation wherein all users have the clearance or 
authorization, documented formal access approval, if required, and the need-to-know for all data 
handled by the AIS. If the AIS processes special access information, all users require formal access 
approval. In the dedicated mode, an AIS may handle a single classification level and/or category 
of information or a range of classification levels and/or categories. (DODD 5200.28)

Degauss. To apply a variable, alternating current (AC) field for the purpose of demagnetizing 
magnetic recording media, usually tapes. The process involves increasing the AC field gradually 
from zero to some maximum value and back to zero, which leaves a very low residue of magnetic 
induction on the media. (FlPS PUB 39)

Denial of Service. Action or actions that result in the inability of an AIS or any essential part to 
perform its designated mission, either by loss or degradation of operational capability. (DODD 
5200.28)

Designated Approving Authority (DAA). The official who has the authority to decide on 
accepting the security safeguards prescribed for an AIS or the official who may be responsible for 
issuing an accreditation statement that records the decision to accept those safeguards. The DAA 
must be at an organizational level such that he or she has authority to evaluate the overall mission 
requirements of the AIS and to provide definitive directions to AIS developers or owners relative 
to the risk in the security posture of the AIS. (DODD 5200.28)

Emission Security. The protection resulting from all measures taken to deny unauthorized persons 
information of value that might be derived from intercept and from an analysis of compromising 
emanations from systems. (NCSC-TG-004)

Evaluated Products List (EPL). A documented inventory of equipments, hardware, software, 
and/or firmware that have been evaluated against the evaluation criteria found in DOD 5200.28-
STD. (DODD 5200.28)

Formal Access Approval. Documented approval by a data owner to allow access to a particular 
category of information. (DODD 5200.28)

Identification. The process that enables, generally by the use of unique machine- readable names, 
recognition of users or resources as identical to those previously described to an AIS. (DOD 
5200.28-M)

Information System Security Officer (ISSO). A person responsible to the DAA for ensuring that 
security is provided for and implemented throughout the life cycle of an AIS from the beginning 
of the concept development phase through its design, development, operation, maintenance, and 
secure disposal. (DODD 5200.28)

Information Systems Security (INFOSEC). A composite of means to protect 
telecommunications systems and automated information systems, and the information they 
process. (AR 380-19)

Isolation. The containment of users and resources in an AIS in such a way that users and processes 
are separate from one another as well as from the protection controls of the operating system. (FlPS 
PUB 39)

Least Privilege. This principle requires that each subject in a system be granted the most 
restrictive set of privileges (or lowest clearance) needed for the performance of authorized tasks. 
The application of this principle limits the damage that can result from accident, error, or 
unauthorized use. (DOD 5200.28-STD)

Multilevel Secure. A class of system containing information with different sensitivities that 
simultaneously permits access by users with different security clearances and need-to-know, but 
prevents users from obtaining access to information for which they lack authorization. (DOD 
5200.28-5TD)

Multilevel Secure Mode. A mode of operation that allows two or more classification levels of 
information to be processed simultaneously within the same system when not all users have a 
clearance, authorization, or formal access approval for all information handled by the AIS. (DODD 
5200.28)

Need-To-Know. The necessity for access to, knowledge of, or possession of specific information 
required to carry out official duties. (NCSC-TG-004-88)

Network. A network is composed of a communications medium and all components attached to 
that medium whose responsibility is the transference of information. Such components may 
include AISs, packet switches, telecommunications controllers, key distribution centers, and 
technical control devices. (DODD 5200.28)

Network Trusted Computing Base (NTCB). The totality of protection mechanisms within a 
network system-including hardware, firmware, and software-the combination of which is 
responsible for enforcing a security policy. The NTCB is the network generalization of the trusted 
computing base (TCB). (NCSC-TG-01 1)

Open Security Environment. An environment that includes those systems in which one of the 
following conditions holds true:

a. Application developers (including maintainers) do not have sufficient clearance or 
authorization to provide an acceptable presumption that they have not introduced malicious 
logic. (See Closed Security Environment for an explanation of sufficient clearance.)

b. Configuration control does not provide sufficient assurance that applications are protected 
against the introduction of malicious logic prior to and during the operation of system 
applications. (NCSC-TG-004-88)

Orange Book. Common name for Department of Defense Trusted Computer System Evaluation 
Criteria, DOD 5200.28-STD.

Partitioned Mode. A mode of operation in which all persons have the clearance, but not 
necessarily the need-to-know and formal access approval, for all data handled by the AIS. This 
mode encompasses compartmented mode as defined by DCID 1/16. (DODD 5200.28)

Password. A private character string that is used to authenticate an identity. (DOD 5200.28-STD)

Periods Processing. A security mode of operation and/or maximum classification of data handled 
is established for an interval of time, then changed for the following interval of time. The period 
extends from the time when the system is securely initialized to the time when the system is purged 
of all sensitive data handled during the processing period. (DODD 5200.28)

Personnel Security. The procedures established to insure that all personnel who have access to 
any sensitive information have the required authorities as well as all appropriate clearances. (FlPS 
PUB 39)

Physical Security. (1) The use of locks, guards, badges, and similar administrative measures to 
control access to the computer and related equipment. (2) The measures required for the protection 
of the structures housing the computer, related equipment and their contents from damage by 
accident, fire, and environmental hazards. (FlPS PUB 39)

Procedural Security. Synonym for administrative security.

Risk. A combination of the likelihood that a threat will occur, the likelihood that a threat 
occurrence will result in an adverse impact, and the severity of the resulting adverse impact. 
Reducing either the threat or the vulnerability reduces the risk. (DODD 5200.28)

Risk Analysis. An analysis of system assets and vulnerabilities to establish an expected loss from 
certain events based on estimated probabilities of occurrence. (DODD 5200.28)

Risk Management. The total process of identifying, measuring, and minimizing uncertain events 
affecting AIS resources. It includes risk analysis, cost benefit analysis, safeguard selection, 
security test and evaluation, safeguard implementation, and systems review. (DODD 5200.28)

Security Features. The security-relevant functions, mechanisms, and characteristics of AIS 
hardware and software (e.g., identification, authentication, audit trail, and access control). (DODD 
5200.28)

Security Mode. A mode of operation in which the DAA accredits an AIS to operate. Inherent with 
each of the four security modes (dedicated, system high, multilevel, and partitioned) are 
restrictions on the user clearance levels, formal access requirements, need-to-know requirements, 
and the range of sensitive information permitted on the AiS. (DODD 5200.28)

Security Policy. The set of laws, rules, and practices that regulate how an organization manages, 
protects, and distributes sensitive information. (DOD 5200.28-STD)

Security Safeguards. The protective measures and controls that are prescribed to meet the security 
requirements specified for an AIS. These safeguards may include, but are not necessarily limited 
to, hardware and software security features; operation procedures; accountability procedures; 
access and distribution controls; management constraints; personnel security; and physical 
structures, areas, and devices. (NCSC-TG-004-88)

Sensitive Compartmented Information (SCI). Classified information about or derived from 
intelligence sources, methods, or analytical processes that is required to be handled exclusively 
within formal access control systems established by the Director, Central Intelligence. (DODD 
5200.28)

Sensitive Unclassified Information. Any information the loss, misuse, or unauthorized access to, 
or modification of which, might adversely affect U.S. national interest, the conduct of DOD 
programs, or the privacy of DOD personnel (e.g., FOIA exempt information and information 
whose distribution is limited by DOD Directive 5230.24). (DODD 5200.28)

Special Access Program. Any program imposing need-to-know or access controls beyond those 
normally required for access to Confidential, Secret, or Top Secret information. Such a program 
includes, but is not limited to, special clearance of investigative requirements, special designation 
of officials authorized to determine need-to-know, or special lists of persons determined to have a 
need-to-know. (DODD 5200.28)

System High Security Mode. A mode of operation wherein all users having access to the AIS 
possess a security clearance or authorization, but not necessarily a need-to-know, for all data 
handled by the AIS. If the AIS processes special access information, all users must have formal 
access approval. (DODD 5200.28; AFR 205-16)

Technical Vulnerability. A hardware, firmware, communication, or software flaw that leaves a 
computer processing system open for potential exploitation, either externally or internally, thereby 
resulting in risk for the owner, user, or manager of the system. (NCSC-TG-004-88; AR 380-19)

TEMPEST. The study and control of spurious electronic signals emitted from AIS equipment. 
(DOD 5200.28-STD)

Threat. Any circumstance or event with the potential to cause harm to a system in the form of 
destruction, disclosure, modification of data, and/or denial of service. (NCSC-TG-004-88)

Trusted Computing Base (TCB). The totality of protection mechanisms within a computer 
system - including hardware, firmware, and software - the combination of which is responsible for 
enforcing a security policy. A TCB consists of one or more components that together enforce a 
unified security policy over a product or system. The ability of a TCB to correctly enforce a 
security policy depends solely on the mechanisms within the TCB and on the correct input by 
system administrative personnel of parameters (e.g., a user s clearance) related to the security 
policy. (NCSC-TG-004-88; AFR 205-16)

Trusted Products. Products evaluated and approved for inclusion on the Evaluated Products List 
(EPL). (DODD 5200.28)

Users. People or processes accessing an AIS either by direct connections (i.e., via terminals) or 
indirect connections (i.e., prepare input data or receive output that is not reviewed for content or 
classification by a responsible individual). (DODD 5200.28; AFR 205-16; AR 380-19)

Vulnerability. A weakness that may be exploited by a threat agent to cause harm to the AIS. The 
totality of susceptibilities to specific attack and the opportunity available to a hostile entity to 
mount that attack. (NCSC-TG-004-88)

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