Serialize Helper class for encrypt and serialize any object collection in C#

SeralizeHelper.cs

 public static class SerializeHelper
    {
        static byte[] key = { 1, 2, 3, 4, 5, 6, 7, 8 };  
                                                         
        static byte[] iv = { 1, 2, 3, 4, 5, 6, 7, 8 };
        static DESCryptoServiceProvider des = new DESCryptoServiceProvider();

        public static void SerialiZe<T>(T data, string path)
        {
            using (var fs = new FileStream(path, FileMode.Create, FileAccess.Write))
            using (var cryptoStream = new CryptoStream(fs, des.CreateEncryptor(key, iv), CryptoStreamMode.Write))
            {
                BinaryFormatter formatter = new BinaryFormatter();

                // This is where you serialize the class
                formatter.Serialize(cryptoStream, data);

            }
        }
        public static T DeserialiZe<T>(string path)
        {
            using (var fs = new FileStream(path, FileMode.Open, FileAccess.Read))
            using (var cryptoStream = new CryptoStream(fs, des.CreateDecryptor(key, iv), CryptoStreamMode.Read))
            {
                BinaryFormatter formatter = new BinaryFormatter();


                var deserialized = (T)formatter.Deserialize(cryptoStream);
                return deserialized;
            }
        }
       
    }
    
    //usage
    
     ObservableCollection<CustomClass> obList = new ObservableCollection<CustomClass>();
     CustomClass obj= new CustomClass();
     obj=new CustomClass(Value);
     obList.Add(obj);
     //Serialize
     SerializeHelper.SerialiZe<ObservableCollection<<CustomClass>>(obList, @"data.pk");
     
     //deserialize
     var List = SerializeHelper.DeserialiZe<ObservableCollection<PackageClass>>(@"data.pk");