caesars-cipher

Explaining

The Caesar's cipher is and old encryption method invented by roman emperor Julius Caesar to communicate with their generals.

Encrypt

This technique is based on replacing a letter of the alphabet by another in a given number of spaces.

Example

Spaces = 3
Phrase = 'Hello, World!' Encrypted = 'khoor, zruog!'

Spaces, exclamation and question marks, as well as periods and commas are maintained

Decrypting

Params
- encrypted phrase
- number of spaces

 const encryptedPhrase = phrase.toLowerCase();
 // Make the phrase lowercase

 let phraseLetters = [];
 for(let i = 0; i < encryptedPhrase.length; i++) {
   phraseLetters.push(encryptedPhrase[i]);
 }
 // Create an array with each letter of the original sentence

 let decryptedLetter;
 phraseLetters.map(letter => {
   letter.match(/[\d\s,\.?!]/) 
     ? decryptedLetter = letter
     : decryptedLetter =  findMatch(letter);
     // Map the "letters" array and find the correct
     // match for each one with findMatch() function

   decryptedPhrase += decryptedLetter;
 });
 // Create the decrypted string

It's done!