The Enigma Machine was a piece of cryptographic hardware used by the German military during World War II; successful cryptanalysis was routinely applied against it and the scheme was considered broken. Questions relating to this machine should use this tag and you may also which to use the historic tag.
Questions tagged [enigma]
82 questions
12
votes
2 answers
Under what conditions did a Bletchley bombe stop?
I am trying to understand the conditions necessary for one of the Bletchley Park bombes to stop. Let me give an example.
I have been experimenting with Enigma machine and bombe simulators to try to understand better how the bombe works.
Using a…
Geoff
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7
votes
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culling equivalent Enigma keys for short messages
The following for-loop iterates over all possible keys for an M3 Enigma for three selected rotors:
for start_pos_left in A..Z:
for start_pos_middle in A..Z:
for ring_middle in 1..26:
for start_pos_right in A..Z:
…
Will
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6
votes
2 answers
When does the first rotor in Enigma machine rotate?
I read a ton of articles about the Enigma machine. And the one thing that I can't get is when the first rotor stars rotating.
Some articles says the rotor rotates after the first letter of message has been encrypted. So if the first rotor is set to…
Igor234
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3
votes
1 answer
Enigma machine Encryption steps
I am trying to build a simulated enigma machine.I am basing it off of this one https://www.101computing.net/enigma-machine-emulator/
I have setup the 3 rotors and I am having trouble understanding the rings and rotations. For example I have set the…
eetar1
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3
votes
1 answer
Theory Question with Enigma
I have been reading a bit about how the Enigma machine was cracked in WW2.
There was also this wonderful post which highlighted a lot of useful information.
Let's assume I know everything about how the M3 Army Enigma machine works according to…
big jump
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3
votes
1 answer
Enigma message decode errors, and protocols to prevent them
I was looking at some Enigma messages for some random reasons, and I wondered if there were ever issue pulling the correct words out the strings of characters of if there was a protocol for it. For instance, here is a decoded message from…
b degnan
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3
votes
2 answers
A Modernized Enigma?
I've seen answers here and elsewhere discussing how well the WWII Enigma could hold up to modern cryptanalysis, however, those answers always seem to assume the WWII conditions where the Germans had a limited number of rotor constructions, repeated…
thebaker
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3
votes
2 answers
Why isn't my Enigma simulator working?
I am attempting a to simulate an 'Enigma M3' machine. As I understand it, the M3 is internally wired…
RQDQ
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3
votes
0 answers
Enigma rotor settings and the notch
According to
https://www.reddit.com/r/cryptography/comments/v0sw2r/enigma_ring_settings_question/
While the rotor is in the machine, the ring+notch+rotor all rotate in
sync. While the rotor is pulled out, the ring+notch can be detached
and rotated…
pengu1n
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2
votes
2 answers
Is a long Enigma message vulnerable to the index of coincidence?
Let's say we have a ciphertext of length 1000. We try to decipher it with an Enigma machine with random rotors and initial positions but no plugboard (so only $5 * 4 * 3 * 26^3 \approx 2^{20}$ possibilities). Assuming we find the correct settings…
Katoptriss
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2
votes
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Why are there only 10 plugboard pairs in the enigma?
The plugboard provides a new layer of security for the enigma but why can we only swap at most 10 letters? I only found things like "10 was the most common." but why stop there? Isn't adding more going to provide more security?
At first, I thought…
Zara
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2
votes
1 answer
Explanation of Enigma rotor movement
I found this explanation of Enigma rotor movement on this website, but can't quite understand the methodology: Enigma rotation example
A ⤑ B → D ⤑ C (rotor III in position B)
C ⤑ C → D ⤑ D (rotor II in position A)
D ⤑ D → F ⤑ F (rotor I in position…
KevP
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2
votes
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How does a ring affect an inverse rotor?
Rotor I with ring A would look like this:
ABCDEFGHIJKLMNOPQRSTUVWXYZ
↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓
EKMFLGDQVZNTOWYHXUSPAIBRCJ
Inverse rotor I with ring A would look like…
haierophanto
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2
votes
1 answer
What's different between ground setting and ring set in the Enigma machine?
I am writing a python program for the Enigma machine. I know what the ground setting (Grundstellung) is but I don't know the difference between ground setting and ring setting.
What's different between ground setting and ring set in the Enigma…
Ramtin Moradi
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2
votes
3 answers
How much would removing enigmas biggest flaw improve it?
Enigma's biggest flaw was that a letter could never be encrypted as itself. How much would enigma's security increase if it were possible that a letter could be encrypted as itself? I know that would void the method used by Turing and co.
Please…
Legorooj
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