C#

user_password = cipher_utility.Encrypt<RijndaelManaged>(result, "xxxx", "xxxxxxxxx");

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Security.Cryptography;
using System.IO;

namespace Application_Class_Library
{
    public class cipher_utility
    {
        public static string Encrypt<T>(string value, string password, string salt) where T : SymmetricAlgorithm, new()
        {
            DeriveBytes rgb = new Rfc2898DeriveBytes(password, Encoding.Unicode.GetBytes(salt));

            SymmetricAlgorithm algorithm = new T();

            byte[] rgbKey = rgb.GetBytes(algorithm.KeySize >> 3);
            byte[] rgbIV = rgb.GetBytes(algorithm.BlockSize >> 3);

            ICryptoTransform transform = algorithm.CreateEncryptor(rgbKey, rgbIV);

            using (MemoryStream buffer = new MemoryStream())
            {
                using (CryptoStream stream = new CryptoStream(buffer, transform, CryptoStreamMode.Write))
                {
                    using (StreamWriter writer = new StreamWriter(stream, Encoding.Unicode))
                    {
                        writer.Write(value);
                    }
                }

                return Convert.ToBase64String(buffer.ToArray());
            }
        }

        public static string Decrypt<T>(string text, string password, string salt) where T : SymmetricAlgorithm, new()
        {
            DeriveBytes rgb = new Rfc2898DeriveBytes(password, Encoding.Unicode.GetBytes(salt));

            SymmetricAlgorithm algorithm = new T();

            byte[] rgbKey = rgb.GetBytes(algorithm.KeySize >> 3);
            byte[] rgbIV = rgb.GetBytes(algorithm.BlockSize >> 3);

            ICryptoTransform transform = algorithm.CreateDecryptor(rgbKey, rgbIV);

            using (MemoryStream buffer = new MemoryStream(Convert.FromBase64String(text)))
            {
                using (CryptoStream stream = new CryptoStream(buffer, transform, CryptoStreamMode.Read))
                {
                    using (StreamReader reader = new StreamReader(stream, Encoding.Unicode))
                    {
                        return reader.ReadToEnd();
                    }
                }
            }
        }
    }
}

comboBoxLSKFontSize.Items.Add("10";);
comboBoxLSKFontSize.Items.Add("11";);
comboBoxLSKFontSize.Items.Add("12";);
comboBoxLSKFontSize.Items.Add("13";);
comboBoxLSKFontSize.Items.Add("14";);
comboBoxLSKFontSize.Items.Add("15";);
comboBoxLSKFontSize.Items.Add("16";);
stringLSKFontSize = "14";
i = 0;
foreach (string str in comboBoxLSKFontSize.Items)
{
    if (stringLSKFontSize == str)
    {
        comboBoxLSKFontSize.SelectedIndex = i;
        break;
    }
    i++;
}