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Enigma Home Page
Special uses US 6812 Bombe Report |
IntroductionThis software, in C language, emulates in text mode, a Turing/Welchman three rotors Bombe. This model allows you to find the daily key for messages encrypted with the Enigma I or M3 which only uses three rotors. These are the main featuresBy default, a stop displays only one connector (stecker). An option (machine gun) allows you to see all the connectors. The order of the rotors (grundstellung) must be completely specified. The cabling of the rotors is stored in files in the ROT directory. It is easy to add more. You can use Bletchley Park conventions and compare your results with real data from the war, especially those provided in the document “US 6812 Bombe Report” (see links). This simulator passes all of the tests described in the previous report. The simulator supports the Query-Menu. Easy to use1)We create a file describing a "Crib"$ cat ellsbury.cri4 ZZABE ZZBED ZZCAB ZZDCG ZZEHE ZZFHA ZZGEH ZZHAD ZZIDB =E=A= +++++ 2)We start the search, example$ bombe ellsbury.cri4 II I III STOP ellsbury.cri4 II I III BGX E:X ++++++++++++++++++++++++++++++++++++++++++++ The format of a Crib fileEach line begins with the position of the three rotors followed by a couple of letters: the letter in clear and the corresponding ciphered letter. Then we have a line, for example "=E=A=" which specifies that the electric current is sent to the terminal "A" of the letter "E". The end of the file is specified by the line “+++++”.
Menu
Enigma 012345678
ZZZZZZZZZ (position of the left rotor)
5 ZZZZZZZZZ (position of the middle rotor)
A-----H Grund. ABCDEFGHI (position of the right rotor)
/| || plain BEACHHEAD
7/ |2 4||6 cipher EDBGEAHDB
D--B-----E
|8 0 | Input letter: E, terminal: A
| 1 | 4 loops
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The arguments of the bombe software: The software displays, if it finds solutions, the word "STOP" followed by the order of the rotors (Walzenage), the position of each rotor (Grundstellung) and the stecker that corresponds to the letter choosen in the menu (here, the letter "E"). Exhaustive searchThe Bombe software only searches for a specific combination of rotors, for example "IV-I-III". Another software, les_bombes.pl, written in Perl, allows you to search for a set of combinations. It just calls the software Bombe and he gives it these combinations. Without argument, the software only uses the first three rotors (I, II, III). with the argument "soixante" he uses the five Army (or Air) rotors. Finally, with the argument "naval", it uses the eight rotors of the navy. Example: +++++++++++++++++++++++++++ $ perl les_bombes.pl ellsbury.cri4 soixante ===> ( 1) I II III ===> ( 2) I III II ===> ( 3) II I III STOP ellsbury.cri4 II I III BGX E:X ===> ( 4) II III I ===> ( 5) III I II ===> ( 6) III II I STOP ellsbury.cri4 III II I EFO E:N ===> ( 7) I II IV … Advanced useThe Bombe software has several options. To show them, just launch the software without arguments. $ ./bombe.exe Usage: bomb3r [options] crib left middle right -step : Stop after each grundstellung -stop : Stop after each stop -register : Print registers -printall : Print all registers -testall : Test all registers -back : Back one a position for a stop -mg : Machine Gun -sss : Self-steckers needed (SSS) -csko : Steckers no adjacent (CSKO) -nodiag : Not use the Diagonal Board -bp : Use BP notation, use drums B-* ! -ts : Use Tony Sale notation, use -ring ZZZ -ukw XXX : Uncle Walter (Default: B) -ws XXX : Wheels Start (Default: AAA) -ring XXX : Ringstellung (default: AAA) You can download the softwares here
A Bombe simulator in ExcelAlberto Bernasconi created a Bombe of Turing / Welshman in Excel. Alberto gave me permission to host his software. The multiple colors make it very educational.
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