App that survives wipe

Hi,

I want to build an App which survives a system recovery.
What I am was doing is move the APK file to "/system/priv-app", so the App stays on the system even when I wipe everything, for example via ClockWork.

BUT the data and preferences of my App are removed after that, because this data is located under /data/data(?).

Question: How can I store the data and preferences of my app securely even when I wipe the phone?

Thanks!