Encrypted Filesystem Images with TrueCrypt
TrueCrypt is a widely used, open source disk encryption software that allows you to create a large, single, encrypted file that can be mounted as a drive letter and used like any other filesystem.
When the filesystem is unmounted, the encrypted filesystem reverts back to its single, encrypted file.
We are happy to report that the internal structure of truecrypt disk images make it possible to efficiently rsync them to a remote location. This means that after the initial (complete) upload of your TrueCrypt disk image, subsequent uploads will efficiently transfer only the changes that have been made to the encrypted filesystem since its last upload.
We encourage all rsync.net customers to at least familiarize themselves with the TrueCrypt software - it runs on Windows, Mac OSX, and Unix, is free, open source software and is supported both by rsync.net and a large community of developers and end users.
Documentation on creating TrueCrypt volumes can be found here.
Documentation on using system encryption with TrueCrypt can be found here.