Encode/Decode to Base64

//Encode

static public string EncodeTo64(string toEncode)

    {

      byte[] toEncodeAsBytes

            = System.Text.ASCIIEncoding.ASCII.GetBytes(toEncode);

      string returnValue

            = System.Convert.ToBase64String(toEncodeAsBytes);

      return returnValue;

    }

//Decode

    static public string DecodeFrom64(string encodedData)

    {

      byte[] encodedDataAsBytes

          = System.Convert.FromBase64String(encodedData);

      string returnValue =

         System.Text.ASCIIEncoding.ASCII.GetString(encodedDataAsBytes);

      return returnValue;

    }

//Usage

      string myData = “Here is a string to encode.”;

      string myDataEncoded = EncodeTo64(myData);

      Console.WriteLine(myDataEncoded);

      string myDataUnencoded = DecodeFrom64(myDataEncoded);

      Console.WriteLine(myDataUnencoded);

      Console.ReadLine();

Link where I got this from:
http://arcanecode.com/2007/03/21/encoding-strings-to-base64-in-c/