C# - Data Encryption Method

private static void Encrypt (MemoryStream input, string password)
        {
            var value = input.ToArray ();
            var keyBytes = new Rfc2898DeriveBytes (password, Encoding.UTF8.GetBytes (SaltKey)).GetBytes (KeyLength / 8);
            var symmetricKey = new RijndaelManaged { Mode = CipherMode.CBC, Padding = PaddingMode.Zeros };
            var encryptor = symmetricKey.CreateEncryptor (keyBytes, Encoding.UTF8.GetBytes (IVKey));
            using (var outputStream = File.Exists (data) ? File.OpenWrite (data) : File.Create (data)) {
                using (var cryptoStream = new CryptoStream (outputStream, encryptor, CryptoStreamMode.Write)) {
                    cryptoStream.Write (value, 0, value.Length);
                    cryptoStream.FlushFinalBlock ();
                    cryptoStream.Close ();
                    outputStream.Close ();
                }
            }
        }

        private static MemoryStream Decrypt (string password)
        {
            MemoryStream outputStream = new MemoryStream ();
            var keyBytes = new Rfc2898DeriveBytes (password, Encoding.UTF8.GetBytes (SaltKey)).GetBytes (KeyLength / 8);
            var symmetricKey = new RijndaelManaged { Mode = CipherMode.CBC, Padding = PaddingMode.None };
            var decryptor = symmetricKey.CreateDecryptor (keyBytes, Encoding.UTF8.GetBytes (IVKey));
            using (var input = File.OpenRead (data))
            using (var cryptoStream = new CryptoStream (input, decryptor, CryptoStreamMode.Read)) {
                var plainTextBytes = new byte[input.Length];
                var decryptedByteCount = cryptoStream.Read (plainTextBytes, 0, plainTextBytes.Length);
                outputStream.Write (plainTextBytes, 0, decryptedByteCount);
                outputStream.Flush ();
                outputStream.Seek (0, SeekOrigin.Begin);
                cryptoStream.Close ();

                return outputStream;
            }
        }