440:
653:
communications. The military versions were sufficiently different to present an entirely new problem. Having done that much, it was still necessary to check each of the potential daily keys to break an encrypted message (i.e., a "ciphertext"). With many thousands of such possible keys, and with the growing complexity of the Enigma machine and its keying procedures, this was becoming an increasingly daunting task.
461:
27:
694:, "we quickly found the within the , but introduction raised the number of possible sequences of drums from 6 to 60 and hence also raised tenfold the work of finding the keys. Thus the change was not qualitative but quantitative. We would have had to markedly increase the personnel to operate the bombs, to produce the
416:, using the daily key (all the rest of those settings). At this point each operator would reset his machine to the message key, which would then be used for the rest of the message. Because the configuration of the Enigma's rotor set changed with each depression of a key, the repetition would not be obvious in the
708:
that the Poles decided to share their Enigma-breaking techniques and equipment with the French and
British in July 1939 because they had encountered insuperable technical difficulties. Rejewski rejected this: "No, it was not difficulties that prompted us to work with the British and French, but
407:
plugboard. The rotor settings were trigrams (for example, "NJR") to indicate the way the operator was to set the machine. German Enigma operators were issued lists of these keys, one key for each day. For added security, however, each individual message was encrypted using an additional key
652:
was able to determine the internal wiring of the Enigma machine and thus to reconstruct the logical structure of the device. Only general traits of the machine were suspected, from the example of the commercial Enigma variant, which the
Germans were known to have been using for diplomatic
675:
of letters, the bomb method required only unchanged letters. Hence it could be applied even though the number of plug connections in this period was between five and eight. In mid-November 1938, the bombs were ready, and the reconstructing of daily keys now took about two hours.
664:(cryptologic bomb), probably in October 1938. Each bomb (six were built in Warsaw for the Cipher Bureau before September 1939) essentially constituted an electrically powered aggregate of six Enigmas and took the place of some one hundred workers.
690:. On December 15, 1938, two new rotors, IV and V, were introduced (three of the now five rotors being selected for use in the machine at a time). As Rejewski wrote in a 1979 critique of appendix 1, volume 1 (1979), of the official history of
321:
How the machine came to be called a "bomb" has been an object of fascination and speculation. One theory, most likely apocryphal, originated with Polish engineer and army officer
Tadeusz Lisicki (who knew Rejewski and his colleague
371:
was built by the Poles and was a hand operated multiple enigma machine. When a possible solution was reached a part would fall off the machine onto the floor with a loud noise. Hence the name "bombe".
30:
Diagram of
Rejewski's cryptologic bomb. For clarity, only one set of three rotors is shown (1); in reality, there were six such sets. An electric motor (2) turns the rotors. 3: Switches.
344:
Perhaps the most credible explanation is given by a Cipher Bureau technician, Czesław
Betlewski: workers at B.S.-4, the Cipher Bureau's German section, christened the machine a "
403:
to control the operation of the machine: rotor order, which rotors to install, which ring setting for each rotor, which initial setting for each rotor, and the settings of the
431:
malpractice, since the first insights into Enigma encryption could be inferred from seeing how the same character string was encrypted differently two times in a row.
709:
only the deteriorating political situation. If we had had no difficulties at all we would still, or even the more so, have shared our achievements with our allies as
811:
Marian
Rejewski, "Appendix C: Summary of Our Methods for Reconstructing ENIGMA and Reconstructing Daily Keys, and of German Efforts to Frustrate Those Methods in
698:(60 series of 26 sheets each were now needed, whereas up to the meeting on July 25, 1939, we had only two such series ready) and to manipulate the sheets."
334:(the youngest of the three Enigma cryptologists, and who had died in a Mediterranean passenger-ship sinking in January 1942) named the "bomb" after an
671:, on the fact that the plug connections in the commutator ("plugboard") did not change all the letters. But while the grill method required unchanged
950:
777:
656:
In order to mechanize and speed up the process, Rejewski, a civilian mathematician working at the Polish
General Staff's Cipher Bureau in
965:
632:
268:
895:
710:
645:
Using the knowledge that the first three letters of a message were the same as the second three, Polish mathematician–
877:
679:
Up to July 25, 1939, the Poles had been breaking Enigma messages for over six and a half years without telling their
960:
379:
is both vague and inaccurate, as is clear from the device's description at the end of the second paragraph of the "
19:
This article is about the Polish decryption device. For the later
British decryption device at Bletchley Park, see
970:
955:
722:
625:
488:
261:
975:
391:
Enigmas..." Determination of a solution involved no disassembly ("a part... fall off") of the device.
424:
letters would encrypt to different ciphertext letters. (For example, "PDNPDN" might become "ZRSJVL.")
870:
Enigma: How the German
Machine Cipher Was Broken, and How It Was Read by the Allies in World War Two
231:
82:
945:
785:
861:
164:
872:. Translated by Christopher Kasparek. Frederick, Maryland: University Publications of America.
687:
618:
550:
498:
341:
Rejewski himself stated that the device had been dubbed a "bomb" "for lack of a better idea".
302:
254:
243:
53:
35:
668:
200:
865:
843:
605:
513:
503:
478:
70:
58:
8:
235:
929:
508:
400:
331:
239:
180:
65:
218:
873:
695:
353:
899:
338:
of that name. This story seems implausible, since
Lisicki had not known Różycki.
327:
209:
907:
798:
Marian Rejewski, "Appendix E: The Mathematical Solution of the Enigma Cipher" in
748:
728:
649:
528:
427:
This procedure, which seemed reasonably secure to the Germans, was nonetheless a
349:
323:
306:
189:
175:
94:
356:") because of the characteristic muffled noise that it produced when operating.
335:
684:
535:
468:
310:
227:
194:
408:
modification. The operator randomly selected a trigram rotor setting for each
939:
701:
646:
545:
444:
428:
412:(for example, "PDN"). This message key would be typed twice ("PDNPDN") and
151:
120:
115:
834:
540:
518:
417:
75:
421:
443:
Enigma's plugboard, with two cables connected (ten were used during
582:
439:
127:
301:"), was a special-purpose machine designed around October 1938 by
413:
409:
368:
910:(July 1981). "How Polish Mathematicians Deciphered the Enigma".
680:
657:
99:
751:, "Appendix D: How the Polish Mathematicians Broke Enigma" in
460:
758:
587:
575:
570:
565:
560:
555:
364:
132:
26:
20:
447:). This enhancement greatly increased the system's security.
383:" section, below: "Each bomb... essentially constituted an
345:
828:
Marian Rejewski (January 1982). "Remarks on Appendix 1 to
359:
A top-secret U.S. Army report dated 15 June 1945 stated:
725: – Decryption of the cipher of the Enigma machine
326:
in wartime Britain but was never associated with the
667:The bomb method was based, like the Poles' earlier
731: – Cryptologic technique used in World War II
896:"Codebreaking and Secret Weapons in World War II"
778:"The US 6812 Division Bombe Report Eastcote 1944"
937:
711:our contribution to the struggle against Germany
375:The U.S. Army's above description of the Polish
827:
367:" is used to expedite the solution. The first
626:
262:
830:British Intelligence in the Second World War
823:
821:
706:British Intelligence in the Second World War
692:British Intelligence in the Second World War
633:
619:
269:
255:
818:
860:
812:
799:
764:
752:
438:
25:
951:Computer-related introductions in 1938
938:
399:The German Enigma used a combination
13:
912:Annals of the History of Computing
887:
14:
987:
923:
966:Science and technology in Poland
459:
930:Bomba Kryptologiczna Simulator
854:
805:
792:
770:
742:
1:
394:
380:
316:
215:Russian Section cryptologist
170:German Section cryptologists
7:
723:Cryptanalysis of the Enigma
716:
348:" (also, alternatively, a "
159:Chief of Radio Intelligence
10:
992:
434:
18:
454:The Enigma cipher machine
735:
206:Chief of Russian Section
16:Polish decryption device
961:One-of-a-kind computers
161:Chief of German Section
971:Cipher Bureau (Poland)
782:Codesandciphers.org.uk
662:"bomba kryptologiczna"
448:
373:
363:A machine called the "
46:Methods and technology
31:
956:Cryptanalytic devices
894:Momsen, Bill (2007).
866:Kasparek, Christopher
767:, p. 63, note 1.
442:
361:
29:
846:: 75–83, etc. p. 80.
844:Christopher Kasparek
499:Polish Cipher Bureau
385:electrically powered
303:Polish Cipher Bureau
290:bomba kryptologiczna
232:Stanisław Leśniewski
36:Polish Cipher Bureau
862:Kozaczuk, Władysław
842:(1). Translated by
832:by F. H. Hinsley".
330:). He claimed that
236:Stefan Mazurkiewicz
42:
449:
240:Franciszek Pokorny
201:Wiktor Michałowski
165:Maksymilian Ciężki
34:
32:
976:Polish inventions
696:perforated sheets
643:
642:
336:ice-cream dessert
279:
278:
244:Wacław Sierpiński
983:
919:
908:Rejewski, Marian
903:
898:. Archived from
883:
848:
847:
825:
816:
809:
803:
796:
790:
789:
784:. Archived from
774:
768:
762:
756:
746:
635:
628:
621:
463:
451:
450:
309:to break German
299:cryptologic bomb
271:
264:
257:
88:Cryptologic bomb
43:
33:
991:
990:
986:
985:
984:
982:
981:
980:
946:1930s computers
936:
935:
926:
906:
893:
890:
888:Further reading
880:
857:
852:
851:
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813:Kozaczuk (1984)
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800:Kozaczuk (1984)
797:
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771:
765:Kozaczuk (1984)
763:
759:
753:Kozaczuk (1984)
749:Marian Rejewski
747:
743:
738:
729:Zygalski sheets
719:
660:, invented the
650:Marian Rejewski
639:
610:
592:
529:Zygalski sheets
489:Breaking Enigma
483:
437:
420:since the same
397:
350:washing machine
324:Henryk Zygalski
319:
307:Marian Rejewski
275:
246:
242:
238:
234:
230:
226:
221:
219:Piotr Smoleński
217:
212:
208:
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199:
190:Henryk Zygalski
185:
176:Marian Rejewski
167:
163:
160:
158:
154:
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95:Zygalski sheets
59:Enigma "double"
38:
24:
17:
12:
11:
5:
989:
979:
978:
973:
968:
963:
958:
953:
948:
934:
933:
925:
924:External links
922:
921:
920:
904:
902:on 2013-09-13.
889:
886:
885:
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878:
856:
853:
850:
849:
817:
815:, p. 242.
804:
802:, p. 290.
791:
788:on 2009-07-22.
769:
757:
755:, p. 267.
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669:"grill" method
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318:
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311:Enigma-machine
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228:Jan Kowalewski
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195:Antoni Palluth
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918:(3): 213–234.
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879:0-89093-547-5
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704:suggested in
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702:Harry Hinsley
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479:Enigma rotors
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387:aggregate of
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339:
337:
333:
332:Jerzy Różycki
329:
328:Cipher Bureau
325:
314:
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305:cryptologist
304:
300:
296:
293:(Polish for "
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211:
210:Jan Graliński
207:
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182:
181:Jerzy Różycki
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40:Biuro Szyfrów
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28:
22:
932:, David Link
915:
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900:the original
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786:the original
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157:Deputy Chief
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152:Gwido Langer
147:
121:Kabaty Woods
116:Saxon Palace
87:
83:Card catalog
39:
855:Works cited
835:Cryptologia
546:Herivel tip
541:Banburismus
940:Categories
519:Cyclometer
418:ciphertext
395:Background
76:Cyclometer
422:plaintext
414:encrypted
317:Etymology
313:ciphers.
141:Personnel
108:Locations
864:(1984).
717:See also
583:PC Bruno
352:" or a "
128:PC Bruno
868:(ed.).
685:British
597:Related
504:Doubles
435:History
410:message
405:stecker
381:History
369:machine
876:
688:allies
681:French
658:Warsaw
354:mangle
297:" or "
224:Others
100:Lacida
736:Notes
673:pairs
606:Ultra
588:Cadix
576:Hut 8
571:Hut 6
566:Hut 4
561:Hut 3
556:Bombe
524:Bomba
514:Clock
509:Grill
377:bomba
365:bombe
287:, or
284:bomba
148:Chief
133:Cadix
71:Clock
66:Grill
54:"ANX"
21:Bombe
874:ISBN
683:and
551:Crib
346:bomb
295:bomb
281:The
713:."
401:key
389:six
942::
914:.
838:.
820:^
780:.
916:3
882:.
840:6
634:e
627:t
620:v
270:e
263:t
256:v
23:.
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