Best secure/performance way to share medialibrary

So I've got this old iPad 2 which I recently installed XBMC on, so that I could access my medialibrary when im out traveling.
I'm currently sharing my library over the internet with SFTP, which seems fine security wise, but performance wise its quite horrible.

What is the best protocol to use for sharing your files over the internet?

I would also love to know the answer to this. I'm on android, but I'm also using FTP and its slow as hell.

If I were you Idgeinc I'd use Air Video (app+desktop program). It has nothing to do with XBMC but it's great at streaming, which is really what we all want XBMC for anyway!

More often than not, the limiting factor is that the file that plays fine on a local network is just too large and maxes out your internet upstream connection (which is much slower than the downstream connection). There are transcoding servers, like Air Video, that re-encode the files to be smaller and thus play better on the slower upstream connection from your home. I am not sure of any right now that work really well with XBMC itself.

I personally prefer webdav (http) but that also has to do with how i have the rest set up. Firewalls don't give me grief. And I can proxy.

FTP has advantages like support in many phone apps ect because of file listing ability.
But resumed transfers for FTP that start beyond the 2GB position has been known to cause trouble.

There is really no reason to prefer one over the other unless you need to solve some problem.
Like Ned said, upload speed matters. I measured a 480p film at 4,8Mbit upload speed.
And then you have to hope your provider has a stable network and isn't squeezing you off to benefit facebook users.