Best Secure Protocol For Accessing Fileserver over WAN?

I am setting up a home fileserver and would like to be able to mount the filesystem on my laptops running Ubuntu and Mac OS X. I want to be able to mount the filesystem over both the LAN and Internet and so I want the protocol to be secure. I am debating between NFSv4, OpenAFS, and WebDAV. Do you have any recommendations about which filesystem would be best? It seems that OpenAFS is quite secure but creates a meta-filesystem that could make it hard to get my data out in case of a problem.

Or would it be best to set up a VPN for accessing my files securely?

Thanks!

The best way would be to set up an encrypted VPN between your server and you using openvpn

Then you can use samba to listen on the internal network only and mount it as you wish

Thanks, that sounds like a good idea. My only reluctance with using OpenVPN is there is no native client available for my iOS devices, however I can use sftp for the basic file transfers I would need to make.

Since all of my machines that will be accessing the NAS are *NIX I think I'll try NFS before Samba since it supports Linux filesystems better than Samba. The solution you outlined should provide me with the security I'm looking for while also making access to mounting the drives straight forward