*JfA 
'  (j^O    December  23, 1971 
NUMBER  S- 5100.20 
ASD(I) 
SUBJECT 
Department  of  Defense  Directive 
The  National  Security  Agency  and  the  Central 
Security  Service  (U) 
Reference:      (a)  'National  Security  Council  Intelligence 
Directive  No.  6 
I.  PURPOSE 
This  directive  prescribes  authorities,  functions,   and 
responsibilities  of  the  National  Security  Agency  (NSA)  and 
the  Central  Security  Service  (CSS). 
II. 
CONCEPT 
A. 
B. 
C. 
Subject  to  the  provisions  of  NSCID  No.  6,   and  the 
National  Security  Act  of  1947,  as  amended,   and 
pursuant  to  the  authorities  vested  in  the  Secretary  of 
Defense,   the  National  Security  Agency  is  a  separately 
organized  agency  within  the  Department  of  Defense 
under  the  direction,   supervision,  funding,  maintenance 
and  operation  of  the  Secretary  of  Defense. 
The  National  Security  Agency  is  a  unified  organization 
structured  to  provide  for  the  Signals  Intelligence^ 
{SIGINT)  mission  of  the  United  States  and  to  insure 
secure  communications  systems  for  all  departments 
and  agencies  of  the  U.S.  Government^ 
The  Central  Security  Service  will  conduct  collection, 
processing  and  other  SIGINT  operations  as  assigned. 
Excluded  From  Automatic 
5200.10
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Dec  23,  71#  -       •    •  * 
S-5100.20         *  ^ 
III.        DEFINITIONS  "  ■ 
A.  Signals  Intelligence  (SIGINT)  is  a  category  of  intelligence 
'  "  information  comprising  all  Communi cations  Intelligence  " 
f  _  (COMINT),   Electronics  Intelligence  (ELINT),   and 
*  Telemetry  Intelligence  (TELINT). 
j  B.      COMINT  is  technical  and  intelligence  information  derived 
•  *  from  foreign  communications  by  other  than  the  intended  * 
[  *  recipients.     COMINT  is  produced  by  the  collection  and  * 
J  *  processing  of  foreign  communications  passed  by  electro-  * 
r  *  magnetic  means,   with  specific  exceptions  stated  below,  * 
\ :  and  by  the  processing  of  foreign  encrypted  communica- 
[  tions,   however  transmitted.     Collection  comprises  search, 
I  intercept,   and  direction  finding.     Processing  comprises 
|.  range  estimation,   transmitter/operator  identification, 
J  signal  analysis,  traffic  analysis,   cryptanalysis,   decryption, 
:  study  of  plain  text,  the  fusion  of  these  processes,   and  the 
f  reporting  of  results.     COMINT  shall  cot  include: 
\  1.      Intercept  and  processing  of  unencrypted  written 
|«  communications,   except  the  processing  of  written 
plain  text  versions  of  communications  which  have  been 
encrypted  or  are  intended  for  subsequent  encryption. 
2.  Intercept  and  processing  of  press,   propaganda  and 
other  public  broadcasts,   except  for  processing 
encrypted  or  "hidden  meaning"  passages  in  such 
broadcasts. 
3.  Oral  and  wire  interceptions  conducted  under  DoD  * 
Directive  5200.  24. 
4.  Censorship.  ' 
ELINT  is  technical  and  intelligence  information  derived  from 
foreign,  non-communications,   electromagnetic  radiations 
emanating  from  other  than  atomic  detonation  or  radioactive 
sources.     ELINT  is  produced  by  the  collection  (observation 
and  recording),  and  the  processing  for  subsequent  intelligence 
purposes  of  that  information.
r  •     • 
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►  ■ 
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S-5I00.20 
D,  TELINT  is  technical  and  intelligence  information  derived        •* 
-from  the  intercept,-processing,  -and  -analysis  of  foreign 
telemetry. 
E,  SIGINT  operational  control  is  the  authoritative  direction 
of  SIGINT  activities,   including  tasking  and  allocation  of 
effort,   and  the  authoritative  prescription  of  those  uniform 
techniques  and  standards  by  which  SIGINT  information  is 
collected,   processed  and  reported. 
F,  SIGINT  resources  comprise  units  /activities  and  organiza- 
tional elements  engaged  in  the  conduct  of  SIGINT  (COMINT, 
ELINT  or  TELINT)  activities.  * 
VI.       APPLICABILITY 
The  provisions  of  this  directive  apply  to  the  Office  of  the 
Secretary  of  Defense,  the  military  department,   the  Joint 
Chiefs  of  Staff,   the  unified  and  specified  commands,   the 
National  Security  Agency,   the  Central  Security  Service, 
and  other  Defense  agencies  hereinafter  called  Department 
r  of  Defense  components. 
V.         ORGANIZATION  AND  RESOURCES 
A.  The  SIGINT  resources  of  the  Department  of  Defense 
will  be  structured  to  accomplish  most  efficiently 
and  effectively  the  SIGINT  mission  of  the  U.  S. 
B.  The  National  Security  Agency  shall  consist  ef  a 
Director,   a  Headquarters,   and  such  subordinate 
units,   elements,  facilities,  and  activities  as  are
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Dec  23,  71 
S- 5100. 20 
assigned  to  the  National  Security  Agency  by  the  Secretary 
of  Defense  in  his  role  as  the  exe^utivp  a,ETPt  nf  *j^»  — 
Government  for  the  conduct  of  SIGINT. 
r 
j  _  C-  The  Central  Security  Service  is  comprised  of  a  Chief, 
Central  Security  Service,   a  Deputy  Chief,   a  jointly  staffed 
headquarters.   Army,   Navy  /Marine  Corps  and  Air  Force 
Operating  elements,   and  such  other  subordinate  elements 
and  facilities  as  may  be  assigned  to  the  Central  Security 
Service  by  the  Secretary  of  Defense. 
D.  The  Director,  National  Security  Agency,   shall  also  be  the 
Chief,    Central  Security  Service. 
E.  The  Director  of  the  National  Security  Agency /Chief,   Central 
Security  Service  shall  have  a  Deputy  Director  for  the 
National  Security  Agency  and  a  Deputy  Chief,    Central 
Security  Service.     To  provide  continuity  in  SIGINT  matters 
the  Deputy  Director,   National  Security  Agency,   shall  be 
l  a  technically  experienced  civilian.     The  Deputy  Chief, 
?  --  Central  Security  Service,   shall  be  a  commissioned  officer 
.     of  the  military  Services,   of  not  less  than  two  star  rank, 
designated  by  the  Secretary  of  Defense.     The  Deputy  Chief 
will  normally  not  be  selected  from  the  same  military 
Service  as  the  Chief. 
F«  The  Director  and  Deputy  Director  of  tfro  Rational  Security 
Agency  shall  be  designated  by  the  Secretary  nf  rw^n^g 
subject  to  the  approval  of  the  President.     The  Director 
shall  be  a  commissioned  officer  of  the  military  Services, 
y  °P  active  or  reactivated  status,  and  shall  enjoy  not  less 
f  tkan  three  star  rank  during  the  period  of  his  incumbency. 
\  G'  Thfk  director.  National  Security  Agency  /Chief  f   Central 
Security  Service  shall  report  to  the  Secretary  of  Defense. 
H.  The  Commanders  of  the  Service  cryptologic  organizations 
and  their  subordinate  activities  which  conduct  SIGINT 
operations  will  be  subordinate  to  the  Chief,  Central 
Security  Service,  for  all  matters  involving  SIGINT 
activities.    In  this  role  they  will  be  designated  as  Service 
element  commanders  aad^suhordinate  activities  of  the
Dec  23,   71 
S-5100.20 
Central  Securit/  Service.     Unless  otherwise  specifically 
provided  in  this  directive,  the  Service  cryptologic    "" 
....  organizations  will  remain  in  their  parent  Services,    -- 
for  the  purpose  of  administrative  and  logistic  support. 
I.       The  Secretary  of  Defense  with  the  advice  of  the  Joint 
Chiefs  of  Staff  may  specifically  designate  other  SIGINT  - 
related  resources  of  the  Department  of  Defense  which 
will  be  subordinate  to  the  Chief,    Central  Security 
Service  for  SIGINT  operations. 
VI.  RESPONSIBILITIES  AND  FUNCTIONS 
A.      Subject  to  the  direction,  authority  and  control  of  the 
Secretary  of  Defense,  the  Director,   National  Security 
Agency/Chief,    Central  Security  Service  shall: 
1.  Accomplish  the  SIGINT  mission  of  the  National 
Security  Agency /Central  Security  Service. 
2.  Act  as  principal  SIGINT  advisor  to  the  Secretary 
of  Defense,  the  Director  of  Central  Intellieence. 
and  the  Joint  Chiefs  of  Staff.     As  principal  SIGINT 
advisor  to  the  Joint  Chiefs  of  Staff,   the  Director, 
National  Security  Agency  will  keep  the  Joint  Chiefs 
of  Staff  fully  informed  on  SIGINT  matters. 
3.  Exercise  SIGINT  operational  control  over  SIGINT 
activities  of  the  U.  S.   Government  to  respond 
most  effectively  to  military  and  other  SIGINT 
requirements.    In  the  case  of  mobile  military 
SIGINT  platforms,  he  shall  state  movement 
requirements  through  appropriate  channels  to 
the  military  commanders,  who  shaU  retain 
responsibility  for  operational  command  of  the 
vehicles. 
4.  Provide  technical  guidance  to  all  SIGINT  or 
SIGINT -related  operations  of  the  U.S.  Government. 
5.  Formulate  programs,  plans,  policies,  procedures 
and  principles.
6.  Produce  and  disseminate  SIGINT  in  accordance  with  the 
objectives,    requirements  and  priorities  established  by 
the  Director  of  Central  Intelligence.     (This  function  will  ~ 
not  include  the  production  and  dissemination  of  finished 
intelligence  which  are  the  .responsibilities  of  departments 
and  aprftncies  other  than  the  National  Security  Agency/ 
Central  Security  Service. ) 
7.  Manage  assigned  SIGINT  resources,   personnel  and  programs, 
8.  In  relation  to  the  Department  of  Defense  SIGINT  activities, 
prepare  and  submit  to  the  Secretary  of  Defense  a  con- 
solidated  program  and  budget,   and  requirements  for 
military  and  civilian  manpower,  logistic  and  communications 
support,   and  research,  development,  test  and  evaluation, 
together  with  his  recommendations  pertaining  thereto. 
9.  Conduct  research,   development  and  systems  design  to  meet 
the  needs  of  the  National  Security  Agency/Central  Security 
Service  and  coordinate  with  the  departments  and  agencies 
their  related  research,  development,  test  and  evaluation 
in  the  SIGINT  field. 
10.  Determine  and  submit  to  the  Secretary  of  Defense  logistic 
support  requirements  lor  the  National  Security  Aflencv. 
apd  thp  Central  Security  Service,  together  with  specific 
rprommpnr^ations  as  to  what  each  of  the  responsible 
departments  and  agencies  o^  the  Government  should  supply. 
11.  Develop  requisite  security  rules,   regulations  and  standards 
governing  operating  practices  in  accordance  with  the 
policies  of  the  U.S.  Intelligence  Board  and  the  U.  S. 
Communications  Security  Board. 
12.  Prescribe  within  his  field  of  authorized  operations  requisite 
security  regulations  covering  operating  practices,  including 
the  transmission,  handling,  and  distribution  of  SIGINT 
material  within  and  among  the  elements  under  his  control; 
and  exercise  the  necessary  monitoring  and  supervisory 
control  to  ensure  compliance  with  the  regulations.
Dec  23,   71 
S-5100.20 
13.  Make  reports  and  furnish  information  to  the  U.  S. 
Intelligence  Board  or  the  U.  S.    Communications 
Security  Board,   as  required.  _~      7._1     ._-^    ..." 
14.  Respond  to  the  SIGINT  requirements  of  all  DoD 
components  and  other  departments  and  agencies. 
15.  Eliminate  unwarranted  duplication  of  SIGINT 
efforts. 
16.  Standardize  SIGINT  equipment  and  facilities 
wherever  practicable. 
17.  Provide  for  production  and  procurement  of  SIGINT 
equipments. 
18.  Provide  the  Director  of  Central  Intelligence 
through  the  Secretary  of  Defense  with  such  infor- 
mation as  required  on  the  past,   current  and  pro- 
pj^gft^  plans,   programs,   and  costs  of  the  SIGINT 
activities  under  his  control. 
19-      Provide  guidance  to  the  military -departments  to 
effect  and  insure  sound  and  adequate  military  and 
civilian  SIGINT  career  development  and  training 
programs,   and  conductor  otherwise  provide  for, 
necessary  specialized  and  advanced  SIGINT 
training. 
20.  Provide  technical  advice  and  support  to  enhance 
SIGINT  arrangements  with  foreign  governments, 
and  conduct  as  authorized,  SIGINT  exchanges 
with  foreign  governments. 
21.  Pprform  such  other  functions  as  the  Secretary  of 
Defense  assigns. 
VTI.         AUTHORITIES 
A.      Subject  to  the  authority,   direction  and  control  of  thg 
Secretary  of  Defense,  the  Director,   National  Security
Agencv /Chief.    Central  Security  Service,   is  specifically 
"delegated  authority  to:  — 
1.  Exercise  SIGINT  operational  control  over  SIGINT 
activities  of  the  United  States. 
2.  Issue  direct  to  any  of  his  operating  elements  such 
instructions  and  orders  necessary  to  carry  out  his 
responsibilities  and  functions. 
3.  Have  direct  access  to,  and  direct  communications  with, 
any  element  of  the  U.  S.  Government  performing  SIGINT 
functions. 
4.  The  authority  in  paragraphs  1,2  and  3  above  is  subject 
to  review,   approval  and  control  in  accordance  with 
procedures  determined  by  the  Secretary  of  Defense. 
5.  Adjust  as  required,   through  the  Service  cryptologic 
organizations,  personnel  resources  under  his  SIGINT 
operational  control. 
6.  Centralize  or  consolidate  SIGINT  operations  for  which 
he  is  responsible  to  the  extent  desirable,   consistent 
with  efficiency,   economy,   effectiveness,   and  support 
to  field  commanders. 
7.  Submit,  as  appropriate,  concurrent /letter  of  evaluation 
efficiency /fitness  reports  on  the  commanders  of  sub- 
ordinate elements  of  the  Central  Security  Service  in 
accordance  with  parent  Service  procedures. 
8.  Delegate  SIGINT  operational  contiA  of  specified 
SIGINT  resources  and  facilities  for  such  periods  and 
for  such  operational  tasks  as  required  or  as  directed 
by  the  Secretary  of  Defense.      _    .      • 
9.  Prescribe  SIGINT  procedures  for  activities  to  whom 
he  provides  technical  guidance. 
10.      Prescribe,   or  review  and  approve  security  rules, 
regulations  and  instructions,  as  appropriate.
Dec  23,  71 
S-51O0.2O 
11.  Conduct  those  SIGINT  operations  undertaken  in 
support  of  certain  missions  within  the  purview  of 
NSCID  No.   5.  
""* 
12.  Obtain  such  information  and  intelligence  material 
from  the  departments  and  agencies  (military 
departments,   other  Department  of  Defense  agencies, 
or  other  departments  or  agencies  of  the  Govern- 
ment) as  may  be  necessary  for  the  performance  of 
the  National  Security  Agency  /Central  Security 
Service  functions. 
13.  Maintain  a  departmental  property  account  for  the 
National  Security  Agency  and  the  Central  Security 
Service  headquarters. 
B.      Other  authorities,   specifically  delegated  by  the  Secretary 
of  Defense  or  by  other  proper  authority  to  the  Director, 
National  Security  Agency  /Chief,   Central  Security 
Service  in  other  directives  or  issuances,   will  be 
referenced  in  an  Inclosure  to  this  directive. 
VIII.       RELATIONSHIPS 
A.     In  the  performance  of  its  responsibilities  and  functions, 
the  National  Security  Agency  /Central  Security  Service 
shall: 
1.  Coordinate  actions,   as  appropriate,  with  other  DoD 
components,  and  other  departments  and  agencies 
of  the  Government. 
2.  Maintain  direct  liaison,  as  appropriate,  for  the 
exchange  of  information  and  advice  in  the  Held 
of  its  assigned  responsibility  with  other  DoD 
components  and  other  departments  and  agencies 
of  the  Government. 
3.  Coordinate  with  other  DoD  components  and  other 
departments  and  agencies  of  the  Government  to
make  maximum  use  of  established  facilities  to 
preclude  unnecessarily  duplicating  Buch  facilities^ 
4.  Provide  for  direct  liaison  by  representatives  of 
the  intelligence  components  of  individual  depart- 
ments and  agencies  regarding  interpretation  and 
amplification  of  requirements  and  priorities  within 
the  framework  of  objectives,  requirements,  and 
priorities  established  by  the  Director  of  Central 
Intelligence. 
B.      Other  DoD  components  shall  provide  support,  within 
their  respective  fields  of  responsibility,  to  the  Director, 
National  Security  Agency /Chief,   Central  Security 
Service  as  may  be  necessary  to  carry  out  his  assigned 
responsibilities  and  functions. 
IX.  ADMINISTRATION 
A.  To  the  extent  applicable  and  consistent  with  the  functions 
assigned  to  the  National  Security  Agency /Central 
Security  Service,  Department  of  Defense  policies, 
regulations  and  procedures  will  govern. 
B.  The  National  Security  Agency/Central  Security  Service 
will  be  authorized  such  personnel,   facilities,  funds  and 
other  administrative  support  as  the  Secretary  of  Defense 
deems  necessary  for  the  performance  of  its  functions. 
Other  DoD  components  shall  provide  support  for  the 
Agency /Service  as  prescribed  in  specific  directives  or 
support  agreements. 
CANCELLATION 
To  the  extent  they  are  inconsistent  herewith,  DoD  Directive 
S-5100.  20,    "The  National  Security  Agency",  dated  March  19, 
1959,  DoD  Directive  S-3115.  4,   "Communications  Intelligence", 
dated  March  19,   1959,  and  DoD  Directive  S-3115.  2, 
"Electronics  Intelligence",  dated  February  7,   1967  are 
hereby  cancelled.
Dec  23,  71 
S-5100.20 
XI.  EFFECTIVE  DATE  AND  IMPLE MENTATION 
A.  This  directive  is  effective  upon  publication. 
B.  To  meet  the  provisions  of  this  directive,  the  Director, 
National  Security  Agency  will  develop  a  plan  to 
implement  this  directive  including  establishment  of 
the  Central  Security  Service  for  approval  by  the 
Secretary  of  Defense  with  the  advice  of  the  Joint 
Chiefs  of  Staff. 
C.      When  the  Central  Security  Service  is  established  under 
the  terms  of  this  directive  and  the  approved  implement- 
ing plan,   all  Department  of  Defense  components  will 
review  their  existing  directives,  instructions,   and 
regulations  for  conformity  and  submit  necessary 
amendments  thereto  to  the  Assistant  Secretary  of 
Defense  (Intelligence)  within  ninety  (90)  days. 
Enclosure  -  1 
Listing  of  Specific  Delegations 
of  Authority
Dec  23,    71 
S-5100.  20  (Incl  1) 
Listing  of  Specific  Delegations  of  Authority  by  the 
Secretary  of  Defense  to  the  Director  of  the 
National  Security  Agency 
*  1.     Administrative  authorities  required  for  the  adminis- 
tration and  operation  of  the  National  Security  Agency,  as 
prescribed  in  DoD  Directive  5100.23,   dated  May  17,  1967. 
f2.     Authority  to  authorize  or  request  the  procurement  of 
cryptologic  material  and  equipment  by  the  military  departments, 
as  prescribed  in  DoD  Directive  5160.13,   dated  March  20,  1956. 
*3.     Authority  to  establish  and  administer  programs  of 
training,  as  prescribed  in  DoD  Directive  1430.  4,   dated 
<4.     Authority  to  assign  the  classification  of  TOP  SECRET, 
as  prescribed  in  DoD  Directive  5200.  17*dalc.d  Jul y  10,  1968, 
cjujLvmU  JU^  000  *m  Sdob.l  *  Jv*^t » i  /  fOI 
**5.     Authority  to  determine  the  eligibility  of  individual 
civilian  officers  and  employees  to  transport  or  store  their 
privately  owned  motor  vehicles  at  Government  expense,  in 
accordance  with  provisions  of  DoD  Directive  1418.  3,  dated 
June  28,  1965.