Padding problem with AesManaged

EncryptionPaddingProblem.cs

using System;
using System.IO;
using System.Security.Cryptography;
using System.Text;

namespace CryptoTest
{
    class Program
    {
        static void Main(string[] args)
        {
            string text = "Hello World";

            byte[] data = Encoding.UTF8.GetBytes(text);
            byte[] encrypted;
            byte[] decrypted;

            var encryptor = GetEncryptor();
            using (var ms = new MemoryStream())
            using (var encrypt = new CryptoStream(ms, encryptor.CreateEncryptor(), CryptoStreamMode.Write))
            {
                encrypt.Write(data, 0, data.Length);
                encrypt.FlushFinalBlock();
                encrypted = ms.ToArray();
            }

            using (var ms = new MemoryStream(encrypted))
            using (var decrypt = new CryptoStream(ms, encryptor.CreateDecryptor(), CryptoStreamMode.Read))
            {
                decrypted = new byte[ms.Length];
                decrypt.Read(decrypted, 0, decrypted.Length);
            } 
          
            Console.WriteLine("Data length: {0}", data.Length);
            Console.WriteLine("Encrypted length: {0}", encrypted.Length);
            Console.WriteLine("Decrypted length: {0}", decrypted.Length);
            Console.WriteLine();
            Console.WriteLine("Original content:  -{0}-", text);
            Console.WriteLine("Decrypted content: -{0}-", Encoding.UTF8.GetString(decrypted));
            Console.ReadLine();
        }

        private static AesManaged GetEncryptor()
        {
            string key = "this is my super secret key bojah!";
            byte[] keyBytes = Encoding.UTF8.GetBytes(key);
            var rfc = new Rfc2898DeriveBytes(key, keyBytes, 1000);

            var encryptor = new AesManaged();
            encryptor.Key = rfc.GetBytes(16);
            encryptor.IV = rfc.GetBytes(16);
            return encryptor;
        }
    }
}

Pen syntax, men ytelsen er vel som du siker ikke helt optimalt, en ekstra pass gjennom arrayet i hvertfal? Uansett - takk for input :))