Questions tagged [enigma]
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.
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Have any cryptographic breaks been executed in the real world since World War II?
Have there been any publicly known exploits of a cryptographic break in a widely used cryptographic system to actually read encrypted information (or falsely authenticate) since the Ultra program in ...
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How cryptographically secure was the original WW2 Enigma machine, from a modern viewpoint?
If cryptanalysts today were to crack the original Enigma machine, “how fast” or “how easily” could they do it? What methods would they use?
The original cracking was significantly helped by operator ...
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Can an Enigma-style cipher of sufficient complexity be considered secure today?
Regarding the German Enigma machines, if I recall correctly, the reason they were defeated was because the Allies were able to generate a massive database of possible rotor settings, and because the ...
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Are encryption algorithms with fixed-point free permutations inherently flawed?
Flaw in Enigma
One of the Enigma machine's flaw was the derangement (fixed-point free permutation) of the produced ciphertext, or simply put: No plaintext-letter can be enciphered to itself. See this ...
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How to build an electro-mechanical public key cipher machine?
It is generally assumed that asymmetric encryption schemes were invented in 1973 at GCHQ in Britain and, independently, in 1976 at the MIT.
Imagine, if the abstract idea of having a public key and a ...
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Turing's (still?) classified inference engine algorithm?
Does anyone know the algorithm used by Turing's Colossus inference engine, so highly classified that the Brits kept it secret for decades after WW II?
Indeed, it may still be classified. Several ...
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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 ...
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How many possible Enigma machine settings?
I'm trying to calculate the amount of settings the enigma machine has. I have found several sites regarding this topic, but it seems like there are two answers to my question. The first answer is 158,...
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Would adding daily changing nulls in front of their messages have made the Engima harder to crack?
The British decrypted the German enigma because they knew that they would repeat the message key twice at the start of every message.
Of course, technology to encrypt enigma without the repetition ...
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How does the ring settings of enigma change wiring tables?
EDIT: The model I'm trying to make is "Enigma 1". I learned initially about it from a book called "Code Book" and then looked at it in detail from its wikipedia page. The site wont allow me too add ...
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Why does the Bombe not consider the Ringstellung when determining stecker pairs?
I am doing research on the Bombe Machine, and I read that when the Bombe tries to find the stecker (plugboard) partners of letters, it only needs to use the rotor types and arrangement and also the "...
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Is the logic for how the enigma machine worked documented somewhere?
I know that there is a formula to calculate the result of any input but is the logic of how the machine actually worked documented?
I have seen schematics for the circuitry and even a how to make ...
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Does adding more characters to the Enigma rotors improve crypto strength?
This seems like an obvious question but I haven't been able to find it, so here goes:
Enigma is based on an alphabet of A-Z (26 characters); obviously this directly affects message content (e.g. ...
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How to deduce enigma settings given a partial plaintext?
Assuming some large block of text is encrypted with an enigma machine and I only know a small subset of letters before and after encryption, how do I go about figuring out the enigma settings from ...
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culling equivalent Enigma keys for short messages [closed]
The following for-loop iterates over all possible keys for an M3 Enigma for three selected rotors:
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Why is this the inverse of a Enigma Machine rotor?
I am learning about how the Enigma Machine works and I found this example of one letter being encrypted by an Enigma Machine. It shows the letter "G" going through three rotors and then it goes into ...
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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 ...
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A modern rotor machine, could it be any safe?
I wonder if a rotor machine similar to enigma can be considered secure by today's standards under four conditions:
A rotor machine which consists of 50 rotors picked out of a set of 100.
A rotor ...
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What were Alan Turing and their team searching before doing KPA in the movie "The imitation game"?
I just watched the movie "The imitation game" (2014) which is based on Alan Turing's biography.
At some point in the movie the machine built by Turing wasn't fast enough to decrypt the ...
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Was the Enigma's double stepping mechanism intentional?
It's sometimes refered to as the double stepping anomaly, so was it just a design flaw or was it put in place deliberately?
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Get permutations from password
Are there any "good" ways to get a permutation from a password/pass-phrase?
If one, for example, wanted to get a permutation of letters from a password, how might one do that in a smart way? I would ...
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Would the rotors in Enigma machines always advance by one position? Or was there a way to set this?
Before encrypting a letter the first rotor advances by one, right? So there could be a way, once the first rotor turns 26 times, make the second rotor advance two positions instead of one. Or three. ...
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How to recover ring settings for the slow and the middle rotors on Enigma Checking Machine?
Summary: The operation of the Enigma Bombe is well documented. I manage to use it and a candidate checking machine to recover the plugboard pairs and the ring setting for the fast rotor. I struggle to ...
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Could the Enigma algorithm be classified as a Feistel network?
The Enigma algorithm is a encryption method that was developed (I believe) by the Germans in WWII. It went a little something like this:
When a letter was typed on the keyboard of the Enigma machine, ...
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Does machine cryptography only consist of rotor machines?
For the chronological categorisation of cryptography, I have proceeded as follows:
Cryptography by hand (e.g. Caesar, Vigenére, etc., till around 1900/1920)
Cryptography using machines (e.g. Enigma, ...
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Modifying an Enigma machine to allow unchanged letters
One of the biggest flaws of Enigma was that a letter couldn’t represent itself because the route through the machine was one-way. I was thinking a quick fix could be to introduce a rotor position that ...
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Why are the indicator drums of a Bombe machine labelled from A to Z clockwise?
I am researching the Bombe Machine, having just completed a project on the Enigma Machine. I visited The Rutherford Journal - The Turing Bombe, and it claimed that
The scales on the three ...
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Rotor machines: secrecy of the wiring
During the heyday of rotor machines, the internal rotor wiring was always a closely guarded secret. Even fully cleared repair staff was not allowed to do anything that could reveal it.
As the wiring ...
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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 ...
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How can the Enigma's plugboard settings be found with partially known plaintext?
I don't quite understand the procedure described on wikipedia, is there a generalized procedure you can follow to rule out a pairing on the plugboard?
For example, let's say the cipher text is
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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 ...
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Enigma machine rotor internal wiring question
I have a question regarding the internal wiring of the rotors of the Enigma machine.
I'm trying to understand some details about the original Enigma machine. To the best of my understanding, each ...
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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 ...
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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 ...
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Is it right that the Bomba can halt, but give you a different settings other than the one Germans really used for encryption using an Enigma?
Considering different groundsettings for these messages:
AWE RDE
AFR AFG
HIU HKQ (where similar letters were known as (1,4) ,(2,5) females etc.
I think the cipher clerk rotated the rotors based on ...
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Why Rejewski advanced three position for the right rotor in the second set of rotors in the Cyclometer he devised?
In this article about decryption of Enigma(p.259), author says that
the second set of rotors was stepped three positions beyond the groundsetting
in the Cyclometer Rejewski devised. I would like ...
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Why the permutation of the right hand rotor given in Rejewski's paper is $PNP^{-1}$?
I would like to know why the permutation of the right hand rotor given in Rejewski's paper is $PNP^{-1}$. First of all I can't get how he added an $P$(alphabetic permutation) at the front of $N$(...
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Effective key length in Enigma encryption
Each Enigma machine setting induces a certain encryption in the sense of a function from the space of plain texts to the set of cipher texts.
The number of different Enigma machine settings can be ...
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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 ...
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Fastest / easiest way to find rotor wiring without physical inspection on Enigma Machine emulator
We have an Enigma machine emulator we are trying to replicate. Machine has 3 rotor positions and 6 rotors that can be selected. The input goes through 3 rotors then is reflected back to start as is ...
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What was the key length of the Enigma? [closed]
When I type in any plaintext to an Enigma machine (Enigma machine emulator) the substitution does not seem to follow any pattern. In other words, there is no cycle in the use of enciphering alphabets (...
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Was Enigma really that hard to crack, given that you had access to hundreds of messages per network per day?
Well, I guess that I have always been a little bit suspicious ... so to speak ... of the "official stories" about the difficulty of recovering Enigma message texts during WW2, because it seems to me ...
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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 ...
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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 ...
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How exactly is an enigma simulation software supposed to encrypt alphabets?
EDIT: The model I'm trying to make is "Enigma 1". I learned initially about it from a book called "Code Book" and then looked at it in detail from its wikipedia page. The rotor wiring and other ...
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What is the difference in exchanging the Enigma rotors in their slots?
I have a question regarding the exchange of the rotors in a enigma machine.
I know that there are 3 slots and that up to 8 rotors can be used in those slots. What I don't understand is, as all the ...
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Security of permutation cipher
I would like to understand how secure the permutation cipher is.
I would specifically like to understand the following concrete setup: If the alphabet is $L = \{0,1,\dots , 255\}$ and $\sigma_1, \...
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Enigma ring settings - is the relative location of the turnover all that matters?
I understand that the ring setting of an Enigma rotor changes the alignment between the internal wiring and the letters on the ring. For example, in the diagram below, rotor I has ring setting 2 (B), ...
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Enigma: a Question from WW2
I have seen in the Imitation Game that the Germans reset the Enigma at midnight sharp, and then they start messaging by sending the weather report in the morning.
But the device made by Alan Turing, ...
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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 $5 * 4 * 3 * 26^3 \approx 2^{20}$ ...
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