manchester.md

Manchester code

Invented by G.E. Thomas in 1949, the Manchester code (also known as PE / Phase Encoding) is a binary line code mainly used in telecommunication and data storage. The ciphertext has twice the amount of characters after encoding.

Cipher behavior information

• Case sensitive? ❌
• Deterministic? ✓
• Alphabet: 01
• Characters not in alphabet will be: omitted or throwing an error (default)

Default options object

The options are the same for both methods, encode and decode

const options = {
  inverted: false, // Invert the result / treat ciphertext as inverted.
  failOnUnknownCharacter: true, // Should an error be thrown when a character is not included in the alphabet
}

inverted can be used to switch between two implementations. G.E. Thomas' (false) and IEEE 802.3 (true)

Usage

Encoding

Default

import { manchester } from 'cipher-collection'


console.log(manchester.encode('01')) // 0110

Inverted

import { manchester } from 'cipher-collection'

const invertedOptions = { inverted: true }

console.log(manchester.encode('01'), invertedOptions) // 1001

Without error throwing

import { manchester } from 'cipher-collection'

const silentFailOptions = {
  failOnUnknownCharacter: false,
}

console.log(fractionatedMorse.encode('€€€01', silentFailOptions)) // 0110

Decoding

Default

import { manchester } from 'cipher-collection'


console.log(manchester.decode('0110')) // 01

Inverted

import { manchester } from 'cipher-collection'

const invertedOptions = { inverted: true }

console.log(manchester.encode('1001'), invertedOptions) // 01

Without error throwing

import { manchester } from 'cipher-collection'

const silentFailOptions = {
  failOnUnknownCharacter: false,
}

console.log(fractionatedMorse.decode('0', silentFailOptions)) // (empty string)
console.log(fractionatedMorse.decode('€0110', silentFailOptions)) // 01