Enigma

A Cypher Library based on the Enigma Machine.

What is Does

Using the encode method of this module will base64 encode the provided string and cycles it through the configured disks and wire maps effectively encrypting the provided string.

That same string can then be passed into the decode method which will run the string back through the configured disks restoring the original base64 encoded string which is then decoded and returned to the original provided string.

Each character passed into translate is transformed through a set of functions which change configuration on every character passed in.

Letter -> [WireMap] -> [A] -> [AB[i]] -> [B] -> [BC[i]] -> [C]
                                                            |
                                                        [CC[0.5]]
                                                            |
Result <- [WireMap] <- [A] <- [AB[i]] <- [B] <- [BC[i]] <- [C]

Every time a character is cycled through the disks increased the value of i by 1. A Generated disk mapping is created by meshing the disks on either side where one of the disks characters is rotated by the index which creates a new path between each disk on every character.

Because each character passed into translate is changed 11 to 13 times depending on if the resulting character matches a value in the wire map, and each character goes through a different map, the resulting string becomes difficult to decipher without knowing all of the potential path ways.

This also means the the string Hello could potentially become uEk4k.

IMPORTANT

an Encoded String can ONLY be decoded by the exact same configuration. Therefor it is recommended that configuration for the instance be provided.

Usage

import { Enigma } from "@codevachon/enigma";

const EnigmaConfig = "A32,E12,C44,fD,rs,Rv";
const myString = "Lorem Ipsum";

const encoded = new Enigma(EnigmaConfig).encode(myString);
// -> k5lPsgjA8sIpyKp=

const decoded = new Enigma(EnigmaConfig).decode(encoded);
// -> Lorem Ipsum

Configuration

The configuration string is designed to be passed in directly from an environment file. It is a comma separated value list where each value represents a "Disk" configuration or a "Wire Mapping".

Disk Configuration

Example: A34

This value represents a Disk inserted into the Enigma Machine and its starting index from 0.

Disks are labelled A through E and contain wire mappings for characters A through Z, a through z and 0 through 9.

Wire Mapping

Example: hT

This value represents a wire being connected from the first letter to the second letter. As such, each letter can only be used once when configuring the enigma machine. Using values hT and lY as an example: passing the string "hello" through the wire map would produce TeYYo and passing "TeYYo" back through would produce "hello".

Wire Mappings are only done between characters A through Z and a through z

Unmatched Characters

Characters that are unmatched through the system are simply passed through the system unchanged.