Implementasi Caesar Cipher/Encryption menggunakan c#

caesar.cs

using System;

class Program
{
	/// <summary>
	/// Pengkodean Caesar dengan menggeser huruf.
	/// </summary>
	static string Caesar(string value, int shift)
	{
		char[] buffer = value.ToCharArray();
		for (int i = 0; i < buffer.Length; i++)
		{
			// Letter.
			char letter = buffer[i];
			// geser huruf.
			letter = (char)(letter + shift);
			// kurangi 26 saat overflow.
			// tambahkan 26 saat underflow.
			if (letter > 'z')
			{
				letter = (char)(letter - 26);
			}
			else if (letter < 'a')
			{
				letter = (char)(letter + 26);
			}
			// simpan ke buffer
			buffer[i] = letter;
		}
		return new string(buffer);
	}

	/// <summary>
	/// Main program.
	/// </summary>
	static void Main()
	{
		string a = "test";

		string b = Caesar(a, 18);  // encrypt
		string c = Caesar(b, -18); // decrypt

		string d = Caesar(a, 1);   // encrypt
		string e = Caesar(d, -1);  // decrypt

		string f = "exxegoexsrgi";
		string g = Caesar(f, -4);  // decrypt
	}
}