Persistent storage of encrypted data using .Net

byte[] plaintextBytes = GetDataToProtect();
byte[] encodedBytes = ProtectedData.Protect(plaintextBytes, null, DataProtectionScope.CurrentUser);

byte[] encodedBytes = GetDataToUnprotect();
byte[] plaintextBytes[] = ProtectedData.Unprotect(encodedBytes, null, DataProtectionScope.CurrentUser);

FileStream fStream = File.Open("encrypted.txt", FileMode.OpenOrCreate);
        Rijndael RijndaelAlg = Rijndael.Create();
        CryptoStream cStream = new CryptoStream(fStream,
            RijndaelAlg.CreateEncryptor(RijndaelAlg.Key, RijndaelAlg.IV),
                                       CryptoStreamMode.Write);
        StreamWriter sWriter = new StreamWriter(cStream);

        sWriter.WriteLine("Text to encrypt");
        sWriter.Close();
        cStream.Close();
        fStream.Close();