I have a linux system running Debian Wheezy stable on it and am using it as a file repository (not a true file server because I am using BitTorrent sync to move files as I move around the world). Some family has expressed a desire to store data similarly but I would like to give them the space without me necessarily having direct access to their files.
I know there are some sites that if you store files on them they make it a point to let you know that they can't access it or they can't see it, etc. What mechanism are they using to achieve that level of privacy for their users? Are they able to still scan the directories for viruses or malware or by providing that kind of privacy, do they effectively make it where they cannot see the directory to scan? Or is it something else altogether (encryption, etc)?
My apologies if this is better asked somewhere else or if it has already been answered.
Thank you for your help!