3
votes
Under what conditions did a Bletchley bombe stop?
Suppose it is an Army Enigma I. Choose reflector UKW-B or UKW-C. Choose three rotors from I, II, III, IV and V. For each of the 120 reflector/rotors permutations, there are 17,576 starting indicator ...
3
votes
How to recover ring settings for the slow and the middle rotors on Enigma Checking Machine?
In this case there is simply not enough information to make a determination.
The Ringstellung for the middle rotor only comes into play every 25x26=650 steps. A message of length 174 characters only ...
3
votes
Enigma encryption
What you missed is that the signal goes through the plugboard twice.
Quoting Wikipedia:
Current flows from the battery (1) through a depressed bi-directional
keyboard switch (2) to the plugboard (3). ...
2
votes
Why isn't my Enigma simulator working?
Rotors are I, II and III. Rings and indicator settings are at their home positions. Reflector is UKW-B. Suppose $E_0$ is an Enigma I machine without a plugboard; at $t=0$, $n_{\text{indicator}}=1$, i....
2
votes
Why isn't my Enigma simulator working?
Looks like you've misunderstood what happens to the permutation implemented by a rotor when it rotates. If a rotor which does permutation $\pi$ rotates through one step, the permutation it implements ...
2
votes
Enigma encryption
Short answer: Enigma, with or without a plugboard, is self-inverse and never encode to itself. If $\mathtt{A}$ maps to $\mathtt{W}$, for the same machine state $\mathtt{W}$ maps to $\mathtt{A}$.
...
2
votes
Enigma encryption
Here is a partial Enigma schematic showing only 4 keys and light-bulbs, and 6 contacts per reflector (UKW), rotor side, and plug-board (Stecker) side (out of 26 due to space limitation).
Simplified ...
2
votes
How much would removing enigmas biggest flaw improve it?
Remember this was a mechanical device. Holding the signal in the reflector, rotating the device, and then releasing the signal, that would have been very difficult.
But also remember that what made ...
1
vote
Why the permutation of the right hand rotor given in Rejewski's paper is $PNP^{-1}$?
When ring setting is 01 (A) and indicator shown through the corresponding window is A (01) as well, the wiring core is at its home position. Suppose ring setting is $r$ (variable $r$ not letter $\tt R$...
1
vote
Accepted
Enigma Questions: Eliminating the can't encode to itself flaw? Maybe not a flaw
The issue here is that you have a cryptographic scheme that is easy to implement in software, but not in the electro-mechanical technology of the Enigma machine. Mathematically, the Umkehrwalze pairs ...
1
vote
Problem with implementation of Enigma Machine
Not sure if you figured this out. The process flow without the plugboard is more like;
Press key on keyboard.
Right rotor moves one step.
2a) If right rotor notch at prowl, rotate middle rotor
2b) If ...
1
vote
Problem with implementation of Enigma Machine
There are many accessible resources. As @kodlu has suggested, page 25 of the operation manual for the Enigma Cipher Machine Simulator by Dirk Rijmenants has all the necessary information.
Dirk ...
1
vote
Enigma machine rotor internal wiring question
One other point, rotor wiring was not fixed. I'm not sure when they change the rotor, but they had ring settings. This changed the offset of the output side of the rotor. For a rotor where A translate ...
1
vote
Enigma machine rotor internal wiring question
I had this same question and reached out to Dan Perera the Director of the Enigma Museum and EnigmaMuseum.com
We had some back and forth and his last letter sent was this:
Yes. Enigma rotors can be ...
1
vote
Enigma Machine rotors math
There are three small mistakes. The first two are related. Along the outward signal path, you are absolutely right to change the value by +r1 before entering the wire core of rotor α1. It translates ...
1
vote
Enigma - How many possibilities does the plugboard have?
The above answer is correct, but I know from teaching this problem to others some still have trouble grasping why it is right. If that is you, think of it this way:
You have ten wires. Consider them ...
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