Flancer,

Open-E has IPSec built into it. If you go to the Setup, Network tab, you'll find the IPSec function, where you can set the sytem to use IPSec, and set an individual IP address for access, or a range using a subnet mask. Using IPSec will effectively encrypt your data transfer, and allow only IP addresses you specify to connect.

Be aware that encryption does create overhead in your network for data transfer.

Asaph