using System;

using System.Collections.Generic;

using System.IO;

using System.Linq;

using System.Security.Cryptography;

using System.Text;

using System.Threading.Tasks;       

public class Program

{

    public static void Main()

    {

       Decrypt("Rb4N/7+u0I2BXzdOU8K8SClhrdy+pshdKJrYkNCugQsf8h+oAmE1jKqoRUMfUOan","868716596");

    }

     public static void Decrypt(string cipherText, string salt)

        {

            string EncryptionKey = "EASYREWARDZ0123456789RMABCDEFGHIJKLMNOPQRSTUVWXYZ";

            cipherText = cipherText.Replace(" ", "+");

            byte[] cipherBytes = Convert.FromBase64String(cipherText);

            using (Aes encryptor = Aes.Create())

            {

                Rfc2898DeriveBytes pdb = new Rfc2898DeriveBytes(EncryptionKey, Encoding.UTF8.GetBytes(salt));

                encryptor.Key = pdb.GetBytes(32);

                encryptor.IV = pdb.GetBytes(16);

                MemoryStream ms = new MemoryStream();

                using (CryptoStream cs = new CryptoStream(ms, encryptor.CreateDecryptor(), CryptoStreamMode.Write))

                {

                    cs.Write(cipherBytes, 0, cipherBytes.Length);

                    cs.Close();

                }

                cipherText = Encoding.Unicode.GetString(ms.ToArray());

            }

           // return cipherText;

Console.WriteLine(cipherText);

        }

}