Donate for the Cryptome collection of files from June 1996 to the present


6 April 2003
Source: Hardcopy from NSA's National Cryptologic Museum.

See also Joel McNamara's exemplary TEMPEST collection:

http://www.eskimo.com/~joelm/tempest.html

Other TEMPEST documents: http://cryptome.org/nsa-tempest.htm

Likely redacted text in red is taken from the glossary of NACSIM 5000 Tempest Fundamentals:

http://jya.com/nacsim-5000.htm


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NATIONAL
COMMUNICATIONS
SECURITY
COMMITTEE

TEMPEST
GLOSSARY

NATIONAL COMMUNICATIONS SECURITY COMMITTEE
SUBCOMMITTEE ON COMPROMISING EMANATIONS

SCOCE

TEMPEST
COMSEC

Not releasable to contractors or contractor representatives.

This publication is not releasable to the Defense Technical Information Center per
DoD Instruction 5100.38. This publication shall not be further disclosed or released
by any holder without specific prior approval of the Director, NSA/Chief, CSS.

CLASSIFIED BY NCSC
REVIEW ON 30 March 2001

30 March 1981

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NOT RELEASABLE TO FOREIGN NATIONALS


1. This publication consists of covers and numbered pages i and pages 1 through 7.

2. This Glossary shall not be reproduced in its entirety. Extracts may be made but shall be accounted for locally until destroyed.


UNCLASSIFIED

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FOREWORD (U)

This Glossary was prepared by the National Communications Security Committee's Subcommittee on Compromising Emanations (SCOCE). It contains definitions of terms associated with TEMPEST, which is the investigation and study of compromising emanations from electromechanical and electronic communications and noncommunications signal processing equipement.

The terms listed and defined herein, are those which are directly related to the TEMPEST discipline adn could be applied to more than one TEMPEST publication. Engineering and technical terms in common use are not included in the Glossary unless their definitions are altered when these terms are applied to the TEMPEST discipline.

Certain definitions contained herein are classified; the overall classification is SECRET-NOFORN. The classification symbols used for each term are (S), (C), (U) or a combination thereof. The symbol following a term or definition indicates its classification. If both are unclassified, only the symbol "(U)" follows after the term. Documents in which classified definitions are used must, therefore, be appropriately classified as well.

The Glossary is effective immediately. Comments and recommendations concerning these definitions, as well as requests for additional copies of this Glossary, should be addressed to:

Director
National Security Agency
ATTN: Chairman, SCOCE, xxx
Ft. George G. Meade, MD 20755

30 March 1981

xxxxxxxxxxxxxxxxxxx
xxxxxxxxxxxxxxxxxxx
Executive Secretary

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TEMPEST GLOSSARY (U)

A

Access (U) -- The ability and opportunity to obtain knowledge of national security information or to be in a place where once could be expected to gain such knowledge.

[Three lines redacted.]

Acoustic Emanation (U) - Emanations in the form of free-space acoustical energy produced by the operation of a purely mechanical or electromechanical device equipment. Such emanations may be compromising under the definition of "compromising emanations". (C)

Ambient Level (U) -- Ambient levels may be classified in two categories: (a) Test Environment Ambient Level -- Those levels of radiated and conducted noise existing at at specified testy location and time when only the equipment under test is inoperative. Atmospherics, interference from other sources, and circuit noise or other interference generated within the test detection system comprise the "test environment ambient level". (b) Equipment-Under-Test Ambient Level -- Those levels of radiated and conducted noise which originate in the equipment under test and which are not compromising emanations.

Ambiguity (U) -- A condition which precludes positive identification of specific characters and functions utilizing the parameters of the detected signal. This condition exists when the intelligence-related signal emanation can be equated to more than one character or function.

Analog Signal (U) -- A signal whose amplitude, phase or frequency content is continuously proportional to the stimulus.

[Three lines redacted.]

Average Depth of Correct Characters (ADCC) (U) - [3 lines redacted.] (C)

B

[Two lines redacted.]

[Three lines redacted.]

Bit Density Information (U) - [4 lines redacted.] (C)

BLACK (U) -- A term applied to wire lines, components, equipment, and systems which do not handle national security signals, and to areas in which no national security signals occur.

BLACK Line (U) -- Any line, other than primary and secondary RED conductors, external to national security information-processing equipment.

BLACK Signal (U) -- Any signal (e.g., control signal or enciphered signal) which would not divulge national security information if recovered and analyzed.

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C

[Two lines redacted.]

[Two lines redacted.]

Communications Security (COMSEC) (U) -- The protective measures taken to deny unauthorized persons information derived from telecommunications of the United States Government related to national security and to ensure the authenticity of such communications. Such protection results from the application of security measures (including cryptosecurity, transmission security, and emissions security) to electrical systems generating, handling, processing, or using national security information. It also includes the application of physical security measures to communications security information or materials.

Compromise (U) --  Any occurrence which results or can result in unauthorized persons gaining access to national security information.

Compromising Emanations (CE) (U) -- Unintentional intelligence-bearing signals, which, if intercepted and analyzed, dislose the national security information transmitted, received, handled or otherwise processed by any information-processing equipment.

Compromising Emanation Performance Requirement (CEPR) (U) -- The maximum emanation level permitted at the standard measurement point. When the CEPR is met, there will be minimal chance that a compromising emanation will be detected beyond the specified design radius.

Control Line (U) -- Line intended for the transmission of control signals, alarm indicators and fault determination between components of a system.

Controlled Space (U) -- The three-dimensional space surrounding equipments that process national security information within which unauthorized personnel (1) are denied unrestricted access and (2) are either escorted by authorized personnel or are under continual physical or electronic surveillance.

Correlated Emanations (CORR E) (U) -- Detected emanations which correspond to or contain a discernible relationship to any signal or process of known characteristics. Correlated emanations may be compromising under the definition of "compromising emanations".

Countermeasure (U) -- An action, procedure, modification or physical device which is applied to reduce or to inhibit the generation of compromising emanations.

D

Data Related Emanations (DRE) (U) -- Detected emanations which have a discernible relationship with a signal related to data processedd by the EUT, and have been analyzed and determined to be not compromising.

Design Radius (U) -- The radius of the sphere within which compromising emanations from an equipment located at its center will be contained when the equipment meets the compromising emanation performance requirements.

Digital Signal (U) -- A nominally discontinuous electrical signal that changes from one state to another in discrete steps.

[Two lines redacted.]

[Two lines redacted.]

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[Three lines redacted.]

Digraphic Information (U) - [3 lines redacted.]

Digraphic Processing (U) --  Processing where the data (bits) are parallel processed, and the characters are processed two at a time.

Dry Line (U) -- An interface line of the equipment under test which does not carry any signals while TEMPEST tests are in progress.

E

Emanation (U) -- Unintended signals or noise appearing external to an equipment.

Emanations Security (EMSEC) (U) -- This term is no longer used. The definition of telecommunications has been expanded and emission security encompasses the old definition of emanations security.

Emission Security (U) -- That component of communications security (COMSEC) which results 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 and telecommunications systems.

Equipment Ratiation TEMPEST Zone (ERTZ) (U) -- A zone established as a result of determiend or known equipment radiation TEMPEST characteristics. The zone includes all space within which a successful hostile intercept of compromising emanations is considered possible.

Equipment Under Test (EUT) (U) -- An equipment or group of equipments subject to TEMPEST testing.

EUT Exerciser Equipment (U) -- Any equipment or device (not part of the EUT) used during TEMPEST testing to make the equipment under test (EUT) operate; e.g., a similar or complementary equipment for back-to-back operation or an external clock source. This term may be used interchangeably with EUT stimulus equipment.

F

Facility (U) -- A physically definable area consisting of a controlled space which contains national security information-processing equipments.

[Two lines redacted.]

Fingerprint Signal (U) - A unique emanation caused by the processing or transfer of an information unit character, byte, etc.) by the EUT. (Also called signature.)

Fortuitous Conduction (U) -- Emanations in the form of signals propagated along any unintended conductor. Such emanations may be compromising under the definiton of "compromising emanations".

Fortuitous Conductor (U) -- Any conductor which may provide an unintended path for signals. Fortuitous conductors include cables, wires, pipes, conduits, and structural metal work in the vicinity of a ratiation source.

Full Bit Emanation (U) -- An emanation which correlates on a one-to-one basis with the bits of the message code signal.

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G

Generatrix (U) -- The set of letters which are considered to be the cause of a particular received TEMPEST signal, arranged in order of probability.

Generatrix Family (U) -- The groups (sets of generatrices) into which the letters of the alphabet are assigned by the TEMPEST encoder. Also, the groups into which the letters are assigned at the output of the detector for analysis purposes.

Generatrix Sequence (U) -- The sequence of generatrices resulting from a test, where a representative test message for the EUT is processed; one geratrix for each received signal.

H

Hazard (U) -- A measure of both the existence and the compromising nature of an emanation. A hazard exists if and only if compromising emanations are detectable beyond the controlled space.

[Two lines redacted.]

I

Impulsive Emanation (U) -- An emanation composed of impulses.

Information Ratio (IR) (U) -- A measure of the amount of information which can be derived from a detected signal. It is the ratio of the amount of information contained in a signal to the amount of information necessary for 100 percent recovery of plaintext information.

L

Line Conduction (U) -- Emanations produced on any external or interface line of an equipment, which, in any way, alter the signal on the external or interface lines. The external lines include signal lines, control and indicator lines, and a.c. or d.c. powerlines.

M

Monitor Signal (U) -- The signal to which a detected emanation is compared for determing correlation; a monitor is usually a RED signal.

[Three lines redacted.]

Monographic Information (U) - [3 lines redacted.]

Monographic Processing (U) -- Processing where each character is sequentially processed in a bit parallel format.

Multichannel Information (U) -- Information which results when emanations from multiple TEMPEST channels are used to extract information relating to a single message being processed.

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N

National Security Information (U) -- Government-derived classified information or Government-derived unclassified information relating to the national security.

Noise (U) -- Distrubances superimposed upon a signal that tend to obscure its information content.

[Two lines redacted.]

Nontunable (U) -- A term used to describe a test, or test instrumentation, in which frequency coverage is selected in or more discrete increments, i.e., not continuously variable. Nontunable detection systems do not contain a demodulator.

P

Parallel Information Unit (U) -- Two or more bits arranged in a deterministic order which are transferred or stored simultaneously as a unit. One parallel information unit is transferred when a clock or trigger pulse causes the entire unit to be simultaneously gated out of a register or other storage device. Two or more units can form a larger unit.

[Two lines redacted.]

Polygraphic Information (U) - [2 lines redacted.]

Polygraphic Processing (U) --  Processing where the data (bits) are parallel processed, and the characters are processed more than one at a time.

[Four lines redacted.]

[Two lines redacted.]

Powerline Conduction (U) -- See Line Conduction.

[One line redacted.]

[Two lines redacted.]

Primary Red Conductor (U) -- Any conductor intended to carry national securityinformation and terminating in RED equipment or in the RED side of crypto-equipment or isolation devices.

R

Recoverable Zone (U) -- The three-dimensional space surrounding an equipment or system processing national security information within which it is theoretically possible to recover the information processed. For radiated signals, this term may be used interchangeably with Equipment Radiation TEMPEST Zone (ERTZ).

RED (U) -- A term applied to wirelines, components, equipment, and systems which handle national security signals, and to areas in which national security signals occur.

RED/BLACK Concept (U) -- The concept that electrical and electronic circuits, components, equipments, systems, etc., which handle national security plain language information in electric signal form (RED) be separated from those which handle encrypted or non-national security information (BLACK). Under this

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concept, RED and BLACK terminology is used to clarify specific criteria relating to, and to differentiate between such ciruits, components, equipments, systems, etc., and the areas in which they are contained.

RED Line (U) -- A primary or secondary RED conductor.

RED Signal (U) -- Any signal (e.g., plain text, key, subkey, initial fill or control signal) which would divluge national security information if recovered.

Risk (U) -- A measure of a covert agent's access to a national security processing facility and his incentive to mount an attack on this facility.

S

SCOCE (Subcommittee On Compromising Emanations) (U) -- This subcommittee, composed of representatives from various government organizations, is charged with specific responsibilities designed to implement Government-wide programs for the control and suppression of compromising emanations. In carrying out these responsibilities it is an instrument for exchanging TEMPEST information, techniques, and criteria among Government oranizations and their contractors.

Secondary RED Conductor (U) -- Any conductor, other than primary RED, which connects to RED equipment, the RED side of crypto-equipment, or the RED side of isolation devices, which does not intentionally carry national security information, but because of the coupling mechanism with the RED equipment might carry compromising information, is designated secondary RED (e.g., indicator lines, control lines, timing lines, etc.). Power distribution panels and grounding systemss serving RED wire lines and equipments may be also so designated.

[Three lines redacted.]

Short Cycle Operation (U) - A method employed in TEMPEST testing of cryptographic equipments to facilitate identification of key-correlated emanations; whereby, the equipment is modified to generate a repetitive key. (C)

Signal (U) -- A fluctuating quanitity, such as voltage, current, electrical field strength, sound pressure level, etc., the variations of which convery information.

[Three lines redacted.]

Skewed Parallel Signal (U) - [3 lines redacted.] (C)

Standard Measurement Point (U) -- The point where the compromising emanation performance requirement (CEPR) applies. For an electric or magnetic field amnation, the standard measurement point is one meter from the equipment under test. For a conducted emanation, the standard measurement point is the design radius.

T

[One line redacted.]

Telecommunications (U) -- The transmission, communication, or processing of information, including the preparation of such information, by electrical, electromagnetic, electromechanical or electro-optical means. (Note: This definition includes the processing of information b noncommunicating equipment.)

TEMPEST (U) -- A short name referring to investigations and studies of compromising emanations. It is often used synonymously for the term "compromising emanations"; e.g., TEMPEST tests, TEMPEST inspections.

TEMPEST Channel (U) --  An unintentional communications channel which conveys information about the information processed through the intentional information channel.

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TEMPEST Encoding (U) -- An unintentional process which results in the altering of information before it is emitted into the TEMPEST channel.

TEMPEST Test (U) -- A laboratory or on-sote (field) test to determine the nature and amplitude of conducted or radiated signals containing compromising information.

Test Detection System (U) -- The instrumentation used in performing a TEMPEST test including the transducer, detector, display devices, filters, coazial switches, etc.

Test Message (U) -- A series of characters or signals chosen to be processed by the equipment under test during TEMPEST testing.

[Four lines redacted.]

Transition Density Information (U) - [4 lines redacted.] (C)

Tunable (U) -- A term used to describe a test, or test instrumentation designed to cover a fixed frequency range in continuous or stepped contiguou (within the specified bandwidth) increments. Tunable detection systems may contain a demodulator.

U

Undesired Signal Data Emanations (U) -- Compromising emanations or a primary RED line amplitude density spectrum which exceeds limits specified in the applicable TEMPEST standard.

W

Wet Line (U) -- An interface line of the equipment under test, where the signal normally transmitted over the line is present.







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