From a446ec31c712d4a820e2cd484bed97b2a71c9e83 Mon Sep 17 00:00:00 2001
From: s2224834 <46319860+s2224834@users.noreply.github.com>
Date: Thu, 28 Feb 2019 18:48:36 +0000
Subject: [PATCH] Improve Enigma/Bombe descriptions a little.
---
src/core/operations/Bombe.mjs | 2 +-
src/core/operations/Enigma.mjs | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/src/core/operations/Bombe.mjs b/src/core/operations/Bombe.mjs
index 5e128498..f0d7048c 100644
--- a/src/core/operations/Bombe.mjs
+++ b/src/core/operations/Bombe.mjs
@@ -23,7 +23,7 @@ class Bombe extends Operation {
this.name = "Bombe";
this.module = "Default";
- this.description = "Emulation of the Bombe machine used to attack Enigma.
To run this you need to have a 'crib', which is some known plaintext for a chunk of the target ciphertext, and know the rotors used. (See the 'Bombe (multiple runs)' operation if you don't know the rotors.) The machine will suggest possible configurations of the Enigma. Each suggestion has the rotor start positions (left to right) and known plugboard pairs.
Choosing a crib: First, note that Enigma cannot encrypt a letter to itself, which allows you to rule out some positions for possible cribs. Secondly, the Bombe does not simulate the Enigma's middle rotor stepping. The longer your crib, the more likely a step happened within it, which will prevent the attack working. However, other than that, longer cribs are generally better. The attack produces a 'menu' which maps ciphertext letters to plaintext, and the goal is to produce 'loops': for example, with ciphertext ABC and crib CAB, we have the mappings A<->C, B<->A, and C<->B, which produces a loop A-B-C-A. The more loops, the better the crib. The operation will output this: if your menu has too few loops, a large number of incorrect outputs will be produced. Try a different crib. If the menu seems good but the right answer isn't produced, your crib may be wrong, or you may have overlapped the middle rotor stepping - try a different crib.
Output is not sufficient to fully decrypt the data. You will have to recover the rest of the plugboard settings by inspection. And the ring position is not taken into account: this affects when the middle rotor steps. If your output is correct for a bit, and then goes wrong, adjust the ring and start position on the right-hand rotor together until the output improves. If necessary, repeat for the middle rotor.
By default this operation runs the checking machine, a manual process to verify the quality of Bombe stops, on each stop, discarding stops which fail. If you want to see how many times the hardware actually stops for a given input, disable the checking machine.";
+ this.description = "Emulation of the Bombe machine used at Bletchley Park to attack Enigma, based on work by Polish and British cryptanalysts.
To run this you need to have a 'crib', which is some known plaintext for a chunk of the target ciphertext, and know the rotors used. (See the 'Bombe (multiple runs)' operation if you don't know the rotors.) The machine will suggest possible configurations of the Enigma. Each suggestion has the rotor start positions (left to right) and known plugboard pairs.
Choosing a crib: First, note that Enigma cannot encrypt a letter to itself, which allows you to rule out some positions for possible cribs. Secondly, the Bombe does not simulate the Enigma's middle rotor stepping. The longer your crib, the more likely a step happened within it, which will prevent the attack working. However, other than that, longer cribs are generally better. The attack produces a 'menu' which maps ciphertext letters to plaintext, and the goal is to produce 'loops': for example, with ciphertext ABC and crib CAB, we have the mappings A<->C, B<->A, and C<->B, which produces a loop A-B-C-A. The more loops, the better the crib. The operation will output this: if your menu has too few loops or is too short, a large number of incorrect outputs will usually be produced. Try a different crib. If the menu seems good but the right answer isn't produced, your crib may be wrong, or you may have overlapped the middle rotor stepping - try a different crib.
Output is not sufficient to fully decrypt the data. You will have to recover the rest of the plugboard settings by inspection. And the ring position is not taken into account: this affects when the middle rotor steps. If your output is correct for a bit, and then goes wrong, adjust the ring and start position on the right-hand rotor together until the output improves. If necessary, repeat for the middle rotor.
By default this operation runs the checking machine, a manual process to verify the quality of Bombe stops, on each stop, discarding stops which fail. If you want to see how many times the hardware actually stops for a given input, disable the checking machine.";
this.infoURL = "https://wikipedia.org/wiki/Bombe";
this.inputType = "string";
this.outputType = "JSON";
diff --git a/src/core/operations/Enigma.mjs b/src/core/operations/Enigma.mjs
index 77333b18..71593070 100644
--- a/src/core/operations/Enigma.mjs
+++ b/src/core/operations/Enigma.mjs
@@ -22,7 +22,7 @@ class Enigma extends Operation {
this.name = "Enigma";
this.module = "Default";
- this.description = "Encipher/decipher with the WW2 Enigma machine.
The standard set of German military rotors and reflectors are provided. To configure the plugboard, enter a string of connected pairs of letters, e.g. AB CD EF connects A to B, C to D, and E to F. This is also used to create your own reflectors. To create your own rotor, enter the letters that the rotor maps A to Z to, in order, optionally followed by < then a list of stepping points.
This is deliberately fairly permissive with rotor placements etc compared to a real Enigma (on which, for example, a four-rotor Enigma uses the thin reflectors and the beta or gamma rotor in the 4th slot).";
+ this.description = "Encipher/decipher with the WW2 Enigma machine.
Enigma was used by the German military, among others, around the WW2 era as a portable cipher machine to protect sensitive military, diplomatic and commercial communications.
The standard set of German military rotors and reflectors are provided. To configure the plugboard, enter a string of connected pairs of letters, e.g. AB CD EF connects A to B, C to D, and E to F. This is also used to create your own reflectors. To create your own rotor, enter the letters that the rotor maps A to Z to, in order, optionally followed by < then a list of stepping points.
This is deliberately fairly permissive with rotor placements etc compared to a real Enigma (on which, for example, a four-rotor Enigma uses only the thin reflectors and the beta or gamma rotor in the 4th slot).";
this.infoURL = "https://wikipedia.org/wiki/Enigma_machine";
this.inputType = "string";
this.outputType = "string";