|As StuartS advises - consider the ramifications carefully; and pay close attention to security...|
QNAPS provide for that facility/option; check their various options/methods etc. if you have one from them.
Western Digital have their own ways of doing/enabling it too (and when last I checked - an age ago to be fair - they charged for it...) You actually use a WD server facility to achieve the "secure" connection (I think..).
Don't know about the other brands.