Do you have any data that you want to store off line where no one will find it? If so here is a simple solution.
Put the data on a micro SD card. A 128 gig micro SD card is reasonable priced now.
Drill a 1/2" hole in the top of a door about .600" deep. Just deep enough so the card doesn't hit when you close the door. Be careful not to drill too deep or it will be hard to get the card out.
Store the card in the hole you just drilled.