00NPI1'EN'f!ttL 

NATIONAL SECURITY AGENCY 

Washington 25, D. c. 

NSA REGUIATION 

NUMBER 90-2 24 November 1954 

EFFECTIVE UNTIL 1 DECEMBER 1955 UNLESS SOONER 

RESCINDED OR SUPERSEDED 

NOMENCJATURE FOR COMMUNICATIONS SECURITY MATERIALS 

PURPOSE • • • • • • • • • • • • • 

GENEllA.L • • • • • • • • • • • • • • 

SHORT TITLES FOR COMSEC ~QUIPMENT • 

SHORT TITLES FOR COMSEC AIDS. • • • 

CLASSIFICATION. • • 

APPLICATION • • • 

. . . 

• • . . . . . . . . . . IMPLEMENTATION •• . . . . . SUPERVISION . • • • • • • • • • • • . . SECTION I - PURPOSE 

SECTION 

I 

II 

III 

J)I 

v 

VI 

VII 

VIII 

The purpose of this Regulation is to establish and describe a 

system for the assignment of nomenclature to U.S. communications 

security materials produced by, for, or under the authority of ~he 

Director, National Security Agency, ae established by National . Security Council Directive on Communications Security {NSC 168), 20 October 1953, and Department of Defense Directive on Communi .. 

cations Security (DOD c-5200.5), 24 April 1954. 

SECTION II - GENERAL 

1. Communications Security Materials: Communications Secμrity 

n1eterials (hereinafter referred t,o as COMSEC materials) covered by 

this Regulation include the equipments, devices and documents d~scribe4 

below. For the purpose of this Regulation they are classified and de• 

fined according to their basic operational functions. 

a. Crypto-equipments: Equipments, ~nd components thereof' 1 

that perform, or assist in the performance or cryptographic funptiona 

in cryptosystems designed to provide security to teleconmunications. 

b. Crypto-Ancillary Equipments: Equipments, and componant.a 

thereof, that are required and specifically designed tor use with 

crypto-equipments as an integral part of cryptosysteme, but which, 

in themselves, do not perform cryptographic functions or have a 

cryptographic connotation. 

Declassified and approved for release by NSA on 04-01-2014 pursuantto E.O. 1352a 

CONFIDENTJ2A-=L 

'I 
CONli'IBBN'f'.ft<L 

NBA REGULATION NO. 90-~ 24 November 1954 

c. Crypto-Mnnu f'n~ I.urine; ~!']_u:lpmenta: Equipments, and 

components thereof, tho t. ore apN~ I rtcolly designed for, and used in 

i.he mnnufacture and oonoc lo t.cd tea tlne; of CO?-t>EC materials. 

d. Special Purpose Equtpmente: Equipments, end components thereof, that. ore speci.flcally designed l.o perf'orm functions 

related to teleconununlcatlons security but which, in themselves, are 

not en integral port. of nny crypt.oeyetem or manufacturing process. 

e. COMS~C Alda: All materials other than equipments that 

perform or asBTSt in I.be performance of cryptographic-functions, or 

relate to aesocintcd functions and equipments, and are required in 

the operat.ion and maintenance of cryptosyst.ems and components thereof. 

2. Nomenclature System: 

a. The nomenclature system established by, and described in 

this Regulation will be known by the long title of "Nomenclal.ure 

System :for U.S. COMSEC Materiala"; and by t.he short title of "TSEC 

System". 

b. The term "TSEC" (abbreviation for "Telecommunications 

Security") vill be the "system designator". In order to distinguish 

this system from all other nomenclature systems, the term wi11 always 

appear in the official short titles of all materials subject to this 

Regulation. 

c. "TSEC" nomenclature will cons:Iet of a long title (name) 

and a short tltle (type number and I.he system designs-tor); and will 

be assigned to each equipment, major component or item of COMSEC 

materials defined in paragraph 1, above. 

(1) Long tjtl~s w111 be determined by individual 

conaidcrnl.jon of I.he l1nsic function and type of 

each it.em of materinJ to be titled; they will not be 

aosigncli in accorda11cc with a system or format. As 

a rule, they vJll be un ohort and as general ea 

posoibl,.. or appruprlat.c•. (gx.:.1mples: Literal Cipher 

Machine, HpPcch Bcr.uri t.:1 L·:qulpment, DAPHNE Key List, 

Synchron l z j nis \Jn it., 'l'rnnu I a tor.) 

(2} Short t.it.lcs will be l>1Ha?d on the "Table of Indicators" 

shown in Appcnctix. 

(a) SIH>rt t.ill(?S f'or ~qu1.pmentg will be derlved as 

cxplm nC'd in Si~C'1'l(1H CII. 
NSA REGUIATION NO. 90-2 24 November 1954 

(b) Short titles for COMSEC aids will be derived aa 

explained in SECTION IV. 

d. "TSEC" nomenclature will not b~ assigned to parts, sub .. assemblies, sub-units or similar items that will otherwise be subject 

to parts cataloging under other systems. 

SECTION III - SHORT TITLES FOR COMSEC EQUIPMENT 

L Definitions: For the purpose of ass:f.gnment of short titles to 

equipments and components, the following definitions will apply: 

a. Equipment: A single equipment, or a group of two 

(2) or more components which is capable of operating independently 

to perform all the functions required to fulfill an intended COMSEC 

purpose. (Examples: literal cipher machine, teletypewriter security 

equipment, key tape production equipment, tape ehecker.) 

b. Component: 

(1) A group of parts assembled ·together as a unit to 

perform a definite and complete function necessary 

to the operation of the equipment of which it is 

a part. (Examples: cipher unit, key generator, 

alarm unit, stepping unit), or 

(2) A group of parts assembled together as a separately 

removable and replaceable (and accountable, as appropriate) unit, although the group may not, in itself, 

perform a complete function necessary to the operation 

of the equipment of which it is a part. 

(Examples: drawer, cabinet, keyer assembly, tube 

chassis.) 

2. Equipment Short Titles: Equipment short titles will 

contain the following elements, arranged in tl1e order listed: 

a. The system designator "TSEC", followed by a slant line. 

b. A type number consisting of a descriptive digraph, a 

dash and an equipment number. 

(1) Descriptive digraphs will be selected from the Table 

of Indicators: each will include: 

{a) A "Function" indicator, to indicate the basic, 

or general function which the equipment performs. 

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C()NFIDENTIAL 
NSA. REGUIATION NO. 90-2 24 November 1954 

(b) A "Type" indicator, to indicate the general 

type of the equipment. 

(2) Equipment numbers will be selected consecutively 

beginning with l for the first of each series of 

identical descriptive digraphs. 

c. Examples: TSEC/KW-1, TSEC/HY-3, TSEC/MP-7. 

3. Component Short Titles: Component short titles will contain 

the following elements, arranged in the order listed: 

a. A type number consisting or a descriptive trigraph, a 

dash and a component number. 

(1) Descriptive trigraphs will be selected from the 

Table of Indicators; each will include: 

(a) The "Function" and "Type" indicators of the 

equipment of which the component is a part. 

(b) A "Component" indicator, to indicate the specific 

type or function of the component. 

(2) Component numbers will be selected consecutively 

beginning with 1 for the first of each series of 

identical trigraphs. 

b. The system designator "TSEC" preceded by a slant line. 

c. The equipment number o:f the basic equipment. (This number 

will be used only when the component is an integral part of, and can be 

used only with a specific equipment; it will not be used when a component 

can be used with more than one type of equipment.) 

d. Examples: KYC-3/TSEC2, HWH-3/TSEC, MTE-7 /TSEC6. 

4. Development Model Identification: An equipment or component 

that is in research or development will be designated by the addition 

to its basic short title of the letter "D" inclosed in parentheses. 

(Example: TSEC/KI-4(D); KYG-3(D)/TSEC.) 

4. Modification Identification: 

a. Each significant modification to an equipment or 

component that results in the loss of interchangeability of its 

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CONFIDENTIAL 
REF ID:A66119 

co•FIDENTIAL e 

NSA REGUIATION NO. 90-2 24 November 1954 

component parts, but does not affect the cryptographic intercomm.unicability or interchanseability of the equipment or component as 

e whole, with the unmodified version, will be identified by the 

addition of a modification suf'f1x letter to the short title of the 

unmodified version. 

(1) Modification suffix lettera will be selected from 

the normal alphabet beginning with "A" for the 

first modified equipment or component, and will 

appear in the short title immediately following the 

equipment or component number. (Example: TSEC/KX-lmJ 

KLB-3C /TSEC2.) 

(a) Because of poselble confusion with figures, 

the letters "O" and "I" will not be used as 

modification suffix letters. 

b. Each minor modification to en equipment or component 

(minor wiring changes, parts additions or deletions, or other similar 

modifications) that does not, in any way, affect the cryptographic 

interconnnunicabili ty or the interchangeabj_li ty of parts and assemblies, 

will be identified by an appropriate marking placed on the equipment 

or component so modified. The short title of the modified version will 

remain the same as that of the unmodified equipment or component. 

(l) Marking will indicate that equipment or component 

has been modified in accordance with the appropriate 

Modification Instruction (see SECTION IV), (Example: 

MOD. KAB-1). 

(2) Marking will be placed on the equipment as near as 

possible to the nameplate and w:I.11 be made by means 

of stencil, decal or metal plate. Exact location 

and type of marlting will be dependent _up_oJ!._j;he 

size, mechanical construction, :finish and other 

physical characteristics of the equipment or c.omponent concerned, and will be separately determined 

in each case. 

c. When an equipment or component is modified to the extent 

that it is no longer cryptographically intercommunicable with the unmodified version, the equipment or component will be assigned a new 

short title. 

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CONFIDENTIAL 
NBA REGUIATlON NO. 90-2 2~ NOV"ember 1954 

SECTION IV -.SHORT TITLES FOR COMSEC AIDS 

1. COMSEC aide include, but are not necessarily limited to, general 

instructional publications, operation and maintenance manuals, rotors, 

key disks, key lists, codes and ciphers, strips, and one-time tapes end 

pads. 

2. For the purpose of short title assignment, COMSEC aids are 

considered to be components of cryptosystems and will be assigned short 

titles in the same manner as equipment components. 

3. Short titles assigned to each item, set or series of COMSEC aids 

will consist of a descriptive trigraph, a dash, an item nuniber, a slant 

line and the syntem designator, in that order. 

a. Descriptive trigraphs will be selected :from the Table of 

Indicators; each will include: 

( 1) The "Function" indicator "K", to ind.icate that the 

aid per£orms, or aids in the performance of a cryptog~aphic or related function. 

(2) 'l1he "Type" indical:ior "A", to indicate a COMSEC aid. 

(3) A "Component" indicator, to indicate the specific 

type of aid. 

b. Item numbers of all aids, except one-time keying materials, 

will consist only of a number. Individual ite~Jlumbera will be assigned 

consecutively beginning with one £or the first of each aeries of identicel 

trigraphe. 

c. Item nunib~rs of one-time padR will consist of a trigrapb 

series deaignator followed by a nuinber. Trigraph s_~:r~s depJ,.enatore 

will be ansigned consecutively beginning with AAA; individua1 iteine 

within each series will bt~ designated by a number assigned consecutively 

from 1 to 9999. 

d. Item numbers of one-time tapes will consist of a digraph 

series deslgnator followed by a number. Digraph series designators will 

be assigned consecutively b~ginning with AA; individual items within each 

series will be designated by a number assigned consecutively from l to 

99990. 

e. Examples: KAM-1/TSEC, KAB-5/TSEC 1 KAP-AAC1224/TSEC 1 

KAT-AZ3333/TSEC. 

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CONFIDENTIAL 
-09PIFID!l'NTJAI, 

NSA REGUJ..A'rION NO. 90-2 2'1 November 1954 

li. A later edition of a particular item will be :J ndicated by a 

letter placed after the item number. The letters of the alphabet will 

be used consecutively, beginning wiLh A for the second edition of an 

item. (Example: KAM-3A/TSEC.) 

a. Because of poss:l.ble confusion with figures, the letters 11 011 and "I" will not be used as edition indicators. 

5. A supplement to on item will be identified by a dash(-) and 

a number placed after the title of the item to which the supplement 

applies. Where more than one supplement is applicable to a singlP i~em, 

the supplement numbers will be aosigned consecutively, beginning with 

1 for the first supplement. (Example: KAG-3-1/TSEC.) 

SECTION v - CLA.ssnrICATION 

1. Long titles, or names, of COMSEC materials will be classified 

according to their individual content and need not, necessarily, conform to the classification of the named item itself. Every effort should 

be made to select long titles in such a manner that they can be unclassified. 

2. Individual short titles are unclassified. When compiled into 

lists of holdings, a minimum classification of CONFIDENTIAL will apply. 

SECTION VI - APPLICATION 

1. Short titles derived in accordance with this Regulation will be 

assigned to all COMSEC equipments, and components thereofJ that are 

developed, placed in production or modified on and ai'ter l. December 1954J 

and to all COMSEC aids beginning, insorar as possible and practicable, 

with the first editions, series or items published or produced on and 

after that date. 

2. Short titles derived under other nomenclature svst~ms and 

presently assigned to the following types of COMSEC Jlltlterials will be 

changed to conform to this Regulation: ----

a. New types of equipments, and comoonents thereof, that 

are in development or production on 1 December 1954. 

b. All types of' equipments and devices used in the manufacture and associated testing of COMSEC materials. 

c. Equipments and devices now in the hands of the users that 

have a planned combined operational and war reserve life of three (3) 

or more years. 

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CONFIDENTIAL 
C61fti'!flm'fttL 

NSA RF.GUIJ\.TION NO. 90-2 24 November 1954 

3. Short titles derived under other nomenclature systems and 

assigned to the .following types of COMSEC rna1.erials, will not be 

changed to conform to this Regulation: 

a. COMSEC aids that are in distribution, or that are produced , 

or published prior to l December 1954. 

b. Equipments and devices now in the hands of the users that 

have a planned effective operational life of leas than three (3) years 

and are expected to be declared obsolete when withdrawn from use. 

SECTION VII - IMPLEMENTATION 

1. The Deputy Director, Communications Security, is directly 

responsible for the following functions in implementation of this 

Regulation: 

a. Determination and assignment of all new short titles; 

and determination or changes to be made in assigned short titles as 

the result of equipment modifications. 

b. Publication end dissemination to the military services 

and other interested government agencies of all information pertaining 

to the assignment of new, or changes in existing short titles. 

c. Procurement end distribution of all nameplates required 

as the result of modification or redesignation of equipments in the 

hands or the using services end agencies. 

d. All action required to ef.fec t nameplate changes on 

equipments and devices used in the manufacture and associated testing 

of COMSEC materials; and for the initiation of action to effect nameplate changes on equ:tpments and devices in development and procurement. 

2. Nameplate changes on equipments and devices described in 

paragraph ld above will be accomplished at the earliest practicable 

date. 

3. Nameplate changes on equipments and devices in the hands of 

the users will be made in the most economical and practicable manner 

in accordance with schedules to be established by the using services 

and agencies concerned. Target date for completion of all required 

changes is 1July1957· 

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CON FIDE NT li\L 
co•FIDENTIAL e 

S@ai'IBEJN'frAL 

NSA REGULATION NO. 90-2 24 November 1954 

SECTION VIII - SUPERVISION 

Supervision for the implementation of the policy established 

herein is the responsibility of the Deputy Director, Comm.unicationa 

Security. 

BY COMMAND OF LIEUTENANT GENERAL CANINE: 

OFFICIAL: 

Incl: 

Appendix 

DISTRIBUTION II plus 

COMSEC 25 

CIA 

State Dept. 

FBI 

L. B. FROST 

Rear Admiral, u. s. Navy 

Chief of Steff 

• 

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CONFIDENTIAL 
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REF ID:A66119 

CONFDlE!trIAL NOMENCLATURE SYSTEM FOR U.S. CO!ISEC MATERIALS 

("TSEC" SYSTEM) 

TABIE OF INDICATORS 

( 

EQUIPMENT INDICATORS COI-iPONi~NT INDICATORS 

FUNCTimr TYPE 

L.~-----------~---~- K - Cryptographic 

H - Ancillary 

A - COMSEC aid 

G - Key generation 

I - Data transmission (Citrol) 

L - Literal conversion (Cipher) 

H - Manufacturing 0 - Multi-purpose 

S - Special purpose 

P - ~faterials production 

S - Special purpose 

Example:..: 

'.i'SEC/h-Y-1 

Ts...!J rc/·-.! ... -_, ~ 

"'Sl?" ... --''-'1 I·-• .. _-5 

TSSC/KL-W. 

":S3C/KX-.. ~J) 

KYC-4/Tt-:c 

KXD-7/TSEC2 

HWR-3(D)/TSEC 

MPK-4A/TSEC3 

T - Testing, checkj_11g 

U - Television {Civision) 

W - Teletypewriter (Cipher) 

X - Facsimile (Cifax) 

Y - Speech {Ciphony) 

- Sr. 3:"-?. ss · ~""ity equipment,, No. 1 

- ':e i. ... t.y:JC .::.:::illary -eq,uipr.1ent, No. 3 - P=od.uction testir.; e~..;.ipnent, No. S - First modii"icati~~ of literal cipher machir.e, No. 4 - Facsimile securi-::r equipment, No. 2, in development 

- Combining unit,, No. 4 (KY series), for general use 

with speech security eq,uipn'.ents 

- Drawer, Mo. 7 (KX: series), part of facs:illlile 

security equipment, Mo. 2 - Receive terminal, No. 3 (HW series), for general 

use id th teletype ancillary equipments, in 

development 

- First modification of keyL'"lg unit, Mo. 4 

(MP series), part o! production equipment, No. 3 

1 

EQUIPMENI' CO.MPONENI'S 

A - Keying elernent adv-ancing unit 

B - Basic unit, base, cab~t 

C - Combining unit 

D - Drauer, pare 1 

E - Strip, chassis 

F - Frar;ie , rack 

G - Key generator 

H - Keyboard 

I - Translator, reader 

K - Keyiri~ element or unit 

L - Repeater 

M - Memory or storage unit 

0 - Obser-vation unit 

P - Power supply or unit 

R - Receiver 

S - Synchroni2ing unit 

T - Transmitter 

U - Printer 

X - Special purpose unit 

Note : The table of equipme rrt 

'conponent indicators may be 

expanded, as required, to 

include a complete alphabet 

for each Function or for 

each category • 

cm!SEC AIDS 

A - iuthenticaticn sys~en 

B - =!oi:.ifica."ticn ins-.. ~.i,::-:.i·: .... .::: 

C - Code system 

D - Key:::.r-€ disk 

G - Csneral pub:ica~ion 

I .. !!ecognition ar.d/r:..r 

iden:.ificai:.ion s::ste:::. 

K - Key list 

!1 - ~ainter.ance :nam:al 

0 - Cperating manual 

R - Rotor 

S - S-f:.rip 

'!' - ere-t::.r:.e tape