482:, a two-person missile crew receives and verifies an order to launch, but one individual refuses to turn his launch key even after the other threatens to shoot him. Unknown to them, the attack was a simulation; this incident (as well as a significant rate of similar refusals among other missile crews) sets up the basis of the movie, in which the Department of Defense puts the missile launch system under fully automatic control to prevent a future refusal to launch.
71:. Each operator has the key to only one lock, so neither can open the safe alone. Also, each operator has one of two launch keys; once the order is verified, they must insert the keys in slots on the control panel and turn them simultaneously. As a further precaution, the slots for the two launch keys are positioned far enough apart to make it impossible for one operator to reach both of them at once. For additional protection, the crew in another
191:(USAF) policy concerning critical weapons, a no-lone zone is an area for which entry by a single unaccompanied individual is prohibited. The two-person concept requires the presence of at least two individuals knowledgeable of the task(s) to be performed; in addition, each individual must be capable of detecting an incorrect or unauthorized procedure on the part of any others regarding the task(s).
205:
366:
20:
169:
456:, were the two individuals that were authorized to issue a nuclear launch order against a city thought to be harboring a terrorist leader. Ryan refused to validate the launch order and the nuclear attack is aborted. Ryan was serving as the second one because the Secretary of Defense was killed in a terrorist attack.
285:
requires two individuals with different keys if the vault is secured by a key lock system. For bank vaults secured by combination locks, two or more employees may each be given a portion of the combination. None of them knows the entire combination, and all of them must be physically present in order
269:
Dual keys require the authorization of two separate parties before a particular action is taken. The simplest form of dual key security is a lock that requires two keys to open, with each key held by a different person. The lock can only be opened if both parties agree to do so at the same time. In
257:
The two-person rule is used in other safety-critical applications where the presence of two people is required before a potentially hazardous operation can be performed. This is common safety practice in, for example, laboratories and machine shops. In such a context, the additional security may be
183:
is an area that must be staffed by two or more qualified or cleared individuals at all times. The individuals must maintain visual contact with each other and with the component(s) that require the no-lone-zone area designation. Such a zone may contain a cryptographic component, weapon system
426:, when Captain Ramius takes the dead political officer's missile key, a fellow officer, the ship's doctor, requests that he have the key, using the two-person rule as his reason, saying, "The reason for having two missile keys is so that no one man may arm the missiles."
289:
As an extension of the broader rationale for the two-person rule, regulations for some companies or not-for-profit organizations may require signatures of two executives on checks. These rules make it harder for an individual acting alone to defraud the organization.
118:
has pointed out that, once the order is issued, the process is entirely concerned with authenticating the identity of the commanding officers and the authenticity of the order, and there are no safeguards to verify that the order or the person issuing it is actually
159:
At no time can one person have in their possession the combinations or keys to gain lone access to a security container or cryptographic equipment containing COMSEC material. Neither can one person have sole possession of COMSEC material that requires TPI security.
319:
In some correctional facilities, inmates may be given a two-person rule designation, which means that a minimum of two correctional officers must be utilized to move that particular inmate, primarily due to disciplinary reasons or possible officer safety issues.
35:
is a control mechanism designed to achieve a high level of security for especially critical material or operations. Under this rule, access and actions require the presence of two or more authorized people at all times.
586:
by Eric Flint, the nuclear self-destruct device for an important installation requires at least two people to activate. Nonetheless, one person gains access to all the necessary codes and is able to activate the
90:
must agree that the order to launch is valid and then mutually authorize the launch with their operations personnel. Instead of another party who would confirm a missile launch as in the case of land-based
266:, or "immediately dangerous to life or health") function as a team of at least two personnel. There is commonly more than one team in the same environment, but each team operates as a unit.
987:
645:
kills all the silo personnel to take the keys, and then stretches her arms to turn both keys at the same time, launching a nuclear missile intended to destroy
National City.
453:
624:
animated movie, the father's personified emotions initiate punishment for Riley's misbehavior using a two-person rule system to arm a trigger for "putting the foot down".
316:
Finally, the testimony of two witnesses is valuable in various situations to deter a wrongful act or a false accusation of one, or to prove that a wrongful act occurred.
258:
less important than the fact that if one individual is injured the other can call for help. As another example, firefighters operating in a hazardous environment (
868:
495:
one officer pulls a gun on the second officer when given the command to launch nuclear missiles. However, this is not due to a disagreement, but due to direct
380:
910:
565:
281:
Similarly, many banks implement some variant of the two-person rule to secure large sums of money and valuable items. Under this concept, unlocking the
130:
The two-person rule only applies in the missile silos and submarines; there is no check on the US president's sole authority to order a nuclear launch.
127:
was discharged from the Air Force for asking the question, "How can I know that an order I receive to launch my missiles came from a sane
President?"
75:
must verify the authorization code and turn their keys for the missiles to be launched. A total of four keys are thus required to initiate a launch.
63:
launch crews, once a launch order is received, both operators must agree that it is valid by comparing the authorization code in the order against a
959:
568:"). All depictions include voice authorization of the officers involved, while the two-person variant also involved a hand print identification.
596:, Marcus Chaplin and Sam Kendal, the captain and XO respectively, perform a two-person launch procedure, prior to questioning the attack order.
799:
1111:
376:
508:
franchise depicts the two-person rule and other similar variations in critical situations, often concerning arming or cancelling a ship's
814:
937:
889:
534:
297:) can only take place if approved by two authorized users. This helps prevent expensive errors, and makes it more difficult to commit
753:
529:
244:
67:(a special sealed envelope containing a verification code). These Sealed Authenticators are stored in a safe which has two separate
491:
577:, when honey production is ordered to be halted, two workers simultaneously turn their ignition keys to unlock a shutdown button.
468:
222:
399:
1019:
1015:
422:
305:. While such requirements are common in financial systems, they are also used in controls for critical infrastructure, such as
103:(each of these crew members has access only to their key). Some keys are stored in special safes on board which are secured by
1116:
546:
524:
226:
24:
395:
1090:
592:
72:
659:
464:
460:
391:
332:
and/or airlines made the cockpits of aircraft in flight mandatory "two-person" or "no-lone zones" as a result of the
715:
663:, two officers initiate the two-person rule to launch an ICBM, but a termination order comes in at the last moment.
560:
826:
215:
992:
667:
611:
540:
329:
108:
107:. Nobody on board has the combination to open these safes; the unlock key comes as a part of the launch order (
184:
hardware under test, a nuclear weapon, active weapon controls, or other such critical information or devices.
1121:
964:
815:"An Unsung Hero of the Nuclear Age – Maj. Harold Hering and the forbidden question that cost him his career"
605:, the United States initiates a counterattack against the Soviet Union. This includes a complete two-person
555:
333:
188:
704:
680:, an underground Soviet machine requires the two-person rule to open and close a gate to the Upside Down.
620:
337:
68:
771:
637:
654:
the eponymous EMP attack satellite can only be fired in this way at both the
Severnaya and Cuba sites.
734:
710:
628:
448:
341:
173:
518:
in which only the
Captain's authorization was required). Some variants require the authorization of
684:
is forced to turn both keys simultaneously to operate the damaged machine, triggering an explosion.
431:
1096:
988:"'Rule of two': Australia to require two in a cockpit at all times in wake of Germanwings tragedy"
514:
142:
83:
95:, a third officer – the Weapons Officer – must also confirm the launch. In addition, the set of
1087:
1083:
795:
767:
87:
60:
606:
582:
345:
293:
Some software systems enforce a two-person rule whereby certain actions (for example, funds
138:
Two-person integrity (TPI) is the security measure taken to prevent single-person access to
104:
847:
44:
Per US Air Force
Instruction (AFI) 91-104, "the two-person concept" is designed to prevent
776:
676:
642:
306:
274:
W-40 nuclear warheads under dual key control on
Canadian soil, to be used on the Canadian
152:
The use of two combination locks on security containers used to store COMSEC material; and
1056:
53:
149:
The constant presence of two authorized persons when COMSEC material is being handled;
1105:
601:
509:
294:
271:
124:
115:
49:
911:"Germanwings Flight 4U9525: Canadian airlines told to have 2 people in the cockpit"
860:
694:
496:
302:
99:
is distributed among the key personnel on the submarine, and the keys are kept in
1041:
738:
699:
681:
204:
443:
282:
96:
336:
crash. Early on in the investigation of that crash, it was believed from the
650:
573:
504:
310:
79:
19:
168:
914:
551:
478:
45:
155:
The use of two locking devices and a physical barrier for the equipment.
1097:
U.S. DOD nuclear weapons recovery manual with reference to two-man rule
671:
349:
229: in this section. Unsourced material may be challenged and removed.
827:"Debate Over Trump's Fitness Raises Issue of Checks on Nuclear Power"
275:
139:
120:
145:
material and cryptographic manuals. TPI is accomplished as follows:
309:
for electrical power generation, and dangerous operations, such as
298:
167:
18:
263:
100:
92:
632:
359:
198:
1042:"Germanwings crash: Co-pilot Lubitz 'accelerated descent'"
960:"Germanwings Crash: How the Aviation Industry Has Reacted"
792:
Big Red: Three Months On Board a
Trident Nuclear Submarine
938:"CAA changes cockpit policy following Germanwings crash"
387:
829:
at nytimes.com, 4 August 2016 (retrieved 6 August 2016
544:), others just the commanding and executive officers (
435:
when the captain and the executive officer of the USS
262:, interior structure fire, HAZMAT zone, also known as
1057:"Stranger Things Season 3 Movie References Explained"
609:
missile launch sequence taken from the earlier movie
454:Deputy Director of the Central Intelligence Agency
1016:"EASA recommends minimum two crew in the cockpit"
869:National Institute of Standards and Technology
439:disagreed over the release of nuclear weapons.
429:The two-person rule was crucial in the movie
8:
452:, President Robert Fowler and Jack Ryan, as
16:Action only authorized by two or more people
843:
841:
839:
837:
835:
245:Learn how and when to remove this message
897:Department of the Air Force E-Publishing
790:Extract from: Waller, Douglas C. (2001)
348:after locking the cockpit door when the
809:
807:
726:
590:In the first episode of the ABC series
817:slate.com. Retrieved February 13, 2012
23:Sealed Authenticator System safe at a
7:
888:Culver, William C. (26 March 2020).
227:adding citations to reliable sources
813:Rosenbaum, Ron (February 28, 2011)
535:Star Trek III: The Search for Spock
1084:U.S. National Park Service article
492:Command & Conquer: Red Alert 2
390:by removing the content or adding
14:
865:COMPUTER SECURITY RESOURCE CENTER
754:Federation of American Scientists
530:Let That Be Your Last Battlefield
346:deliberately crashed the aircraft
364:
203:
386:Please help Knowledge (XXG) to
344:information, that the co-pilot
214:needs additional citations for
936:Cooke, Henry (27 March 2015).
890:"AIR FORCE INSTRUCTION 91-101"
739:"AIR FORCE INSTRUCTION 91-104"
547:Star Trek: The Next Generation
522:senior officers (the original
340:audio, and later supported by
40:United States: nuclear weapons
1:
270:1963, Canada accepted having
111:) from the higher authority.
25:missile launch control center
850:tpub.com, pp. 3–9 & 3–10
735:Maj Gen Margaret H. Woodward
467:analyst, the second one was
1112:Nuclear command and control
1093:, with details on operation
1138:
561:Star Trek: Deep Space Nine
330:civil aviation authorities
1044:. BBC News. 3 April 2015.
993:The Sydney Morning Herald
772:"Practicing For Doomsday"
541:Star Trek: First Contact
423:The Hunt for Red October
352:left to use the toilet.
328:In late March 2015 many
109:Emergency Action Message
56:by a single individual.
965:The Wall Street Journal
716:Shamir's Secret Sharing
556:Where Silence Has Lease
489:, in the computer game
334:Germanwings Flight 9525
189:United States Air Force
1091:launch control centers
848:"Two-person integrity"
705:Permissive action link
512:mechanism (except for
463:, in which Ryan was a
338:cockpit voice recorder
176:
134:Cryptographic material
28:
1117:Nuclear weapon safety
940:. Fairfax New Zealand
313:research facilities.
171:
73:launch control center
22:
861:"no-lone zone (NLZ)"
711:Separation of duties
449:The Sum of All Fears
388:improve this section
342:flight data recorder
223:improve this article
174:Titan Missile Museum
65:Sealed Authenticator
400:independent sources
286:to open the vault.
27:with two crew locks
1055:McCluskey, Megan.
768:Waller, Douglas C.
515:Star Trek: Voyager
469:Secretary of State
356:In popular culture
177:
84:commanding officer
29:
1088:Minuteman missile
800:978-0-06-019484-0
737:(23 April 2013).
657:In an episode of
631:" episode of the
461:the movie version
417:
416:
324:Civilian aircraft
255:
254:
247:
123:. Notably, Major
105:combination locks
88:executive officer
61:Minuteman missile
1129:
1072:
1071:
1069:
1067:
1052:
1046:
1045:
1038:
1032:
1031:
1029:
1027:
1012:
1006:
1005:
1003:
1001:
984:
978:
977:
975:
973:
956:
950:
949:
947:
945:
933:
927:
926:
924:
922:
907:
901:
900:
899:. p. 46 § 5.2.6.
894:
885:
879:
878:
876:
875:
857:
851:
845:
830:
824:
818:
811:
802:
794:, HarperCollins
789:
787:
785:
770:(4 March 2001).
764:
758:
757:
751:
749:
743:
731:
607:LGM-30 Minuteman
583:Torch of Freedom
412:
409:
403:
368:
367:
360:
307:nuclear reactors
250:
243:
239:
236:
230:
207:
199:
1137:
1136:
1132:
1131:
1130:
1128:
1127:
1126:
1102:
1101:
1075:
1065:
1063:
1054:
1053:
1049:
1040:
1039:
1035:
1025:
1023:
1022:. 27 March 2015
1014:
1013:
1009:
999:
997:
996:. 30 March 2015
986:
985:
981:
971:
969:
968:. 27 March 2015
958:
957:
953:
943:
941:
935:
934:
930:
920:
918:
917:. 27 March 2015
909:
908:
904:
892:
887:
886:
882:
873:
871:
859:
858:
854:
846:
833:
825:
821:
812:
805:
783:
781:
766:
765:
761:
747:
745:
741:
733:
732:
728:
724:
691:
677:Stranger Things
660:Madam Secretary
413:
407:
404:
385:
381:popular culture
369:
365:
358:
326:
251:
240:
234:
231:
220:
208:
197:
166:
136:
59:In the case of
54:nuclear weapons
42:
33:two-person rule
17:
12:
11:
5:
1135:
1133:
1125:
1124:
1122:Access control
1119:
1114:
1104:
1103:
1100:
1099:
1094:
1080:
1079:
1074:
1073:
1047:
1033:
1007:
979:
951:
928:
902:
880:
852:
831:
819:
803:
759:
725:
723:
720:
719:
718:
713:
708:
702:
697:
690:
687:
686:
685:
664:
655:
646:
641:, the villain
625:
616:
597:
588:
578:
569:
500:
483:
474:
473:
472:
440:
427:
415:
414:
379:references to
372:
370:
363:
357:
354:
325:
322:
295:wire transfers
253:
252:
211:
209:
202:
196:
193:
165:
162:
157:
156:
153:
150:
135:
132:
41:
38:
15:
13:
10:
9:
6:
4:
3:
2:
1134:
1123:
1120:
1118:
1115:
1113:
1110:
1109:
1107:
1098:
1095:
1092:
1089:
1085:
1082:
1081:
1077:
1076:
1062:
1058:
1051:
1048:
1043:
1037:
1034:
1021:
1017:
1011:
1008:
995:
994:
989:
983:
980:
967:
966:
961:
955:
952:
939:
932:
929:
916:
912:
906:
903:
898:
891:
884:
881:
870:
866:
862:
856:
853:
849:
844:
842:
840:
838:
836:
832:
828:
823:
820:
816:
810:
808:
804:
801:
797:
793:
779:
778:
773:
769:
763:
760:
755:
740:
736:
730:
727:
721:
717:
714:
712:
709:
706:
703:
701:
698:
696:
693:
692:
688:
683:
679:
678:
673:
669:
665:
662:
661:
656:
653:
652:
647:
644:
640:
639:
634:
630:
626:
623:
622:
617:
614:
613:
608:
604:
603:
602:The Day After
598:
595:
594:
589:
585:
584:
579:
576:
575:
570:
567:
566:The Adversary
563:
562:
557:
553:
549:
548:
543:
542:
537:
536:
531:
527:
526:
521:
517:
516:
511:
510:self-destruct
507:
506:
501:
498:
494:
493:
488:
484:
481:
480:
475:
471:Sidney Owens.
470:
466:
462:
458:
457:
455:
451:
450:
445:
441:
438:
434:
433:
428:
425:
424:
419:
418:
411:
401:
397:
393:
389:
383:
382:
378:
373:This section
371:
362:
361:
355:
353:
351:
347:
343:
339:
335:
331:
323:
321:
317:
314:
312:
308:
304:
300:
296:
291:
287:
284:
279:
277:
273:
267:
265:
261:
249:
246:
238:
228:
224:
218:
217:
212:This section
210:
206:
201:
200:
194:
192:
190:
185:
182:
175:
170:
163:
161:
154:
151:
148:
147:
146:
144:
141:
133:
131:
128:
126:
125:Harold Hering
122:
117:
116:Ron Rosenbaum
112:
110:
106:
102:
98:
94:
89:
85:
81:
76:
74:
70:
66:
62:
57:
55:
51:
48:or malicious
47:
39:
37:
34:
26:
21:
1066:23 September
1064:. Retrieved
1060:
1050:
1036:
1024:. Retrieved
1010:
998:. Retrieved
991:
982:
970:. Retrieved
963:
954:
942:. Retrieved
931:
919:. Retrieved
905:
896:
883:
872:. Retrieved
864:
855:
822:
791:
782:. Retrieved
775:
762:
752:– via
746:. Retrieved
742:(PDF-136 KB)
729:
695:Buddy system
675:
658:
649:
636:
619:
612:First Strike
610:
600:
591:
581:
572:
559:
545:
539:
533:
523:
519:
513:
503:
497:mind control
490:
486:
477:
476:In the film
447:
436:
432:Crimson Tide
430:
421:
420:In the film
405:
375:may contain
374:
327:
318:
315:
303:embezzlement
292:
288:
280:
268:
259:
256:
241:
232:
221:Please help
216:verification
213:
186:
181:no-lone zone
180:
178:
172:Sign in the
164:No-lone zone
158:
137:
129:
113:
77:
64:
58:
43:
32:
30:
780:. p. 3
744:. p. 2
700:Fail-deadly
682:Joyce Byers
618:In Pixar's
593:Last Resort
485:Similar to
114:Journalist
82:, both the
1106:Categories
874:2023-10-22
756:@ fas.org.
722:References
621:Inside Out
550:episodes "
444:Tom Clancy
377:irrelevant
278:missiles.
195:Other uses
46:accidental
651:GoldenEye
638:Supergirl
574:Bee Movie
564:episode "
528:episode "
525:Star Trek
505:Star Trek
392:citations
311:biohazard
80:submarine
1026:28 March
1000:30 March
972:27 March
944:27 March
921:27 March
915:CBC News
784:16 March
748:16 March
689:See also
668:season 3
629:Solitude
627:In the "
552:11001001
487:WarGames
479:WarGames
408:May 2021
396:reliable
272:American
235:May 2021
86:and the
1078:General
674:series
672:Netflix
670:of the
635:series
587:device.
554:" and "
442:In the
437:Alabama
350:captain
187:In the
798:
643:Indigo
446:novel
276:BOMARC
143:keying
140:COMSEC
50:launch
893:(PDF)
707:(PAL)
520:three
299:fraud
283:vault
101:safes
93:ICBMs
78:On a
69:locks
1068:2024
1061:Time
1028:2015
1020:EASA
1002:2015
974:2015
946:2015
923:2015
796:ISBN
786:2015
777:TIME
750:2015
502:The
398:and
264:IDLH
260:i.e.
121:sane
97:keys
31:The
1086:on
666:In
648:In
633:CBS
599:In
580:In
571:In
558:",
532:",
465:CIA
459:In
394:to
301:or
225:by
52:of
1108::
1059:.
1018:.
990:.
962:.
913:.
895:.
867:.
863:.
834:^
806:^
774:.
538:,
179:A
1070:.
1030:.
1004:.
976:.
948:.
925:.
877:.
788:.
615:.
499:.
410:)
406:(
402:.
384:.
248:)
242:(
237:)
233:(
219:.
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
