Encryption with XOR and non-secure PRNG

xor-pseudorandom-encryption.js

function toBinary(plainText) {
  return plainText.split('').map(c => {
    return ('0'.repeat(BIT_COUNT) + c.charCodeAt(0).toString(2)).slice(-BIT_COUNT)
  })
}

function generateKey(len) {
  return ' '.repeat(len * BIT_COUNT).split('').reduce(p => p + ~~(Math.random() * 2), '')
}

function encrypt(binary, key) {
  return binary.reduce((prev, bin, index) => {
    return prev + bin.split('').reduce((p, b, i) => {
      return p + (+b ^ +key[index + i]).toString(2)
    }, '')
  }, '')
}

function decrypt(binary, key) {
  return binary.match(new RegExp(`.{1,${BIT_COUNT}}`, 'g')).reduce((prev, bin, index) => {
    return prev + String.fromCharCode(parseInt(bin.split('').reduce((p, b, i) => {
      return p + (+b ^ +key[index + i])
    }, ''), 2))
  }, '')
}

var valueRangeLimit = 1024 // Assuming that we won't need charCodes greater than 1024 
var BIT_COUNT = Math.log2(valueRangeLimit)

var str = 'merhaba dünya'
var plainBinary = toBinary(str)
var key = generateKey(plainBinary.length)

var encrypted = encrypt(plainBinary, key)
var decrypted = decrypt(encrypted, key)

console.log(encrypted)
console.log(decrypted)