encrypted password in asp.net C#

<div>
        <asp:TextBox ID="TextBox1" runat="server"></asp:TextBox>
        <br />
        <br />
        <asp:Button ID="Button1" runat="server" Text="Button" onclick="Button1_Click" />
        <br />
        <asp:Label ID="Label1" runat="server" Text="Label"></asp:Label>
        <br />
        <asp:Label ID="Label2" runat="server" Text="Label"></asp:Label>
    </div>


using System;
using System.Collections;
using System.Configuration;
using System.Data;
using System.Linq;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Xml.Linq;
using System.Security.Cryptography;

public partial class testpass : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {

    }
    protected void Button1_Click(object sender, EventArgs e)
    {
        string s = TextBox1.Text;
        string pwed = base64Encode(s);
        Label1.Text = pwed;
        //calling function for decode

        string pwed1 = base64Decode(pwed);
        Label2.Text = pwed1;
    }
    private string base64Encode(string sData)
    {
        try
        {
            byte[] encData_byte = new byte[sData.Length];

            encData_byte = System.Text.Encoding.UTF8.GetBytes(sData);

            string encodedData = Convert.ToBase64String(encData_byte);


            return encodedData;

        }
        catch (Exception ex)
        {
            throw new Exception("Error in base64Encode" + ex.Message);
        }
    }
    public string base64Decode(string sData)
    {

        System.Text.UTF8Encoding encoder = new System.Text.UTF8Encoding();

        System.Text.Decoder utf8Decode = encoder.GetDecoder();

        byte[] todecode_byte = Convert.FromBase64String(sData);

        int charCount = utf8Decode.GetCharCount(todecode_byte, 0, todecode_byte.Length);

        char[] decoded_char = new char[charCount];

        utf8Decode.GetChars(todecode_byte, 0, todecode_byte.Length, decoded_char, 0);

        string result = new String(decoded_char);

        return result;

    }

}