Sharing Large Database Backup Among Team

I work on a team of three – five developers that work on an ASP.net web application remotely. We currently run a full local database from a recent backup on all of our machines during development. The current backup, compressed, is about 18 GB.

I’m looking to see if there’s an easier way to keep all of our local copies relatively fresh without each of us individually downloading the 18 GB file over HTTP from our web server on a regular basis. I guess FTP is an option, but it won’t speed the process up at all.

I’m familiar with torrents and the thought keeps hitting me that something like that would be effective, but I’m unsure of the security or the process.