using System;

using System.IO;

using System.Collections.Generic;

public class Program

{

    public static void Main()

    {

        // need to instantiate list somewhere near top

        var byteList = new List<byte>();

        using (var input = GenerateStreamFromString("hello world hello world hello world hello world"))

        {

            input.Seek(0x1D, SeekOrigin.Begin);

            for (var i=0;i<4;i++){

                var byteThatIsRememberedNow = input.ReadByte() ^ 0x149;

                byteList.Add((byte) byteThatIsRememberedNow);

            }

        }

        // you'll need to replace this with something for your text box...

        // couldn't figure out from your question

        for (var i=0;i<byteList.Count;i++){

            Console.WriteLine(byteList[i]);

        }

    }

    // handy! http://stackoverflow.com/a/1879470/3960399

    private static Stream GenerateStreamFromString(string s)

    {

        MemoryStream stream = new MemoryStream();

        StreamWriter writer = new StreamWriter(stream);

        writer.Write(s);

        writer.Flush();

        stream.Position = 0;

        return stream;

    }

}