Caesar Cipher (Cracking Caesar Cipher with the Brute-Force Technique) - Part II

In Part I, I have written code to encrypt the plain text for demonstration purpose . In this article we will use Brute Force technique to decrypt the encrypted message.

Note: please make sure to read articles Brute force and Caesar Cipher before this article.

	using System;
	using System.Linq;
	using System.Text;
	namespace SecureHashingProject
	{
	public class BruteForceCaesarCipher
	{
	private const string Letters = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
	static void Main()
	{
	var message = "CQRB RB CNBC VNBBJPN";
	for (var shiftKey = 0; shiftKey < Letters.Length; shiftKey++)
	{
	var result = new StringBuilder();
	foreach (var m in message)
	{
	if (Letters.Contains(m))
	{
	var num = Letters.IndexOf(m);
	num += shiftKey;
	if (num >= Letters.Length)
	num -= Letters.Length;
	result = result.Append(Letters[num]);
	}
	else
	{
	result = result.Append(m);
	}
	}
	Console.WriteLine($"shift key: {shiftKey}, value: {result}");
	}
	Console.ReadLine();
	}
	}
	}

view raw BruteForceCaesarCipher.cs hosted with ❤ by GitHub

Above code produce below  result, the above code took 17 iteration  to get the actual message.