using (MemoryStream ms = new MemoryStream())
{
XmlSerializer serializer = new XmlSerializer(typeof(List));
serializer.Serialize(ms, this.Soldiers);

data = ReadByteArrayFromInputStream(ms);
ms.Close();
}

using (FileStream fs = File.Create(Path))
{
Aes aes = Aes.Create();
using (CryptoStream cs = new CryptoStream(
fs,
aes.CreateEncryptor(GetKey(), GetIV()),
CryptoStreamMode.Write))
{
cs.Write(data, 0, data.Length);