ciphers.enigma_machine2

Wikipedia: https://en.wikipedia.org/wiki/Enigma_machine Video explanation: https://youtu.be/QwQVMqfoB2E Also check out Numberphile’s and Computerphile’s videos on this topic

This module contains function ‘enigma’ which emulates the famous Enigma machine from WWII. Module includes: - enigma function - showcase of function usage - 9 randomly generated rotors - reflector (aka static rotor) - original alphabet

Created by TrapinchO

Attributes

RotorPositionT

RotorSelectionT

abc

message

reflector

rotor1

rotor2

rotor3

rotor4

rotor5

rotor6

rotor7

rotor8

rotor9

Functions

_plugboard(→ dict[str, str])

https://en.wikipedia.org/wiki/Enigma_machine#Plugboard

_validator(→ tuple[RotorPositionT, RotorSelectionT, ...)

Checks if the values can be used for the 'enigma' function

enigma(, plugb)

The only difference with real-world enigma is that I allowed string input.

Module Contents

ciphers.enigma_machine2._plugboard(pbstring: str) → dict[str, str]

https://en.wikipedia.org/wiki/Enigma_machine#Plugboard

>>> _plugboard('PICTURES')
{'P': 'I', 'I': 'P', 'C': 'T', 'T': 'C', 'U': 'R', 'R': 'U', 'E': 'S', 'S': 'E'}
>>> _plugboard('POLAND')
{'P': 'O', 'O': 'P', 'L': 'A', 'A': 'L', 'N': 'D', 'D': 'N'}

In the code, ‘pb’ stands for ‘plugboard’

Pairs can be separated by spaces :param pbstring: string containing plugboard setting for the Enigma machine :return: dictionary containing converted pairs

ciphers.enigma_machine2._validator(rotpos: RotorPositionT, rotsel: RotorSelectionT, pb: str) → tuple[RotorPositionT, RotorSelectionT, dict[str, str]]

Checks if the values can be used for the ‘enigma’ function

>>> _validator((1,1,1), (rotor1, rotor2, rotor3), 'POLAND')
((1, 1, 1), ('EGZWVONAHDCLFQMSIPJBYUKXTR', 'FOBHMDKEXQNRAULPGSJVTYICZW', 'ZJXESIUQLHAVRMDOYGTNFWPBKC'), {'P': 'O', 'O': 'P', 'L': 'A', 'A': 'L', 'N': 'D', 'D': 'N'})
Parameters:

  • rotpos – rotor_positon

  • rotsel – rotor_selection

  • pb – plugb -> validated and transformed

Returns:

(rotpos, rotsel, pb)

ciphers.enigma_machine2.enigma(text: str, rotor_position: RotorPositionT, rotor_selection: RotorSelectionT = (rotor1, rotor2, rotor3), plugb: str = '') → str

The only difference with real-world enigma is that I allowed string input. All characters are converted to uppercase. (non-letter symbol are ignored) How it works: (for every letter in the message)

  • Input letter goes into the plugboard.

If it is connected to another one, switch it.

  • Letter goes through 3 rotors.

Each rotor can be represented as 2 sets of symbol, where one is shuffled. Each symbol from the first set has corresponding symbol in the second set and vice versa.

example: | ABCDEFGHIJKLMNOPQRSTUVWXYZ | e.g. F=D and D=F | VKLEPDBGRNWTFCJOHQAMUZYIXS |

  • Symbol then goes through reflector (static rotor).

There it is switched with paired symbol The reflector can be represented as2 sets, each with half of the alphanet. There are usually 10 pairs of letters.

Example: | ABCDEFGHIJKLM | e.g. E is paired to X | ZYXWVUTSRQPON | so when E goes in X goes out and vice versa

  • Letter then goes through the rotors again

  • If the letter is connected to plugboard, it is switched.

  • Return the letter

>>> enigma('Hello World!', (1, 2, 1), plugb='pictures')
'KORYH JUHHI!'
>>> enigma('KORYH, juhhi!', (1, 2, 1), plugb='pictures')
'HELLO, WORLD!'
>>> enigma('hello world!', (1, 1, 1), plugb='pictures')
'FPNCZ QWOBU!'
>>> enigma('FPNCZ QWOBU', (1, 1, 1), plugb='pictures')
'HELLO WORLD'
Parameters:

  • text – input message

  • rotor_position – tuple with 3 values in range 1..26

  • rotor_selection – tuple with 3 rotors ()

  • plugb – string containing plugboard configuration (default ‘’)

Returns:

en/decrypted string

ciphers.enigma_machine2.RotorPositionT
ciphers.enigma_machine2.RotorSelectionT
ciphers.enigma_machine2.abc = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ'
ciphers.enigma_machine2.message = 'This is my Python script that emulates the Enigma machine from WWII.'
ciphers.enigma_machine2.reflector
ciphers.enigma_machine2.rotor1 = 'EGZWVONAHDCLFQMSIPJBYUKXTR'
ciphers.enigma_machine2.rotor2 = 'FOBHMDKEXQNRAULPGSJVTYICZW'
ciphers.enigma_machine2.rotor3 = 'ZJXESIUQLHAVRMDOYGTNFWPBKC'
ciphers.enigma_machine2.rotor4 = 'RMDJXFUWGISLHVTCQNKYPBEZOA'
ciphers.enigma_machine2.rotor5 = 'SGLCPQWZHKXAREONTFBVIYJUDM'
ciphers.enigma_machine2.rotor6 = 'HVSICLTYKQUBXDWAJZOMFGPREN'
ciphers.enigma_machine2.rotor7 = 'RZWQHFMVDBKICJLNTUXAGYPSOE'
ciphers.enigma_machine2.rotor8 = 'LFKIJODBEGAMQPXVUHYSTCZRWN'
ciphers.enigma_machine2.rotor9 = 'KOAEGVDHXPQZMLFTYWJNBRCIUS'