This is the ideal design, along with an office whose job it is to manually move data from the public side to the private side. These offices usually have a server on the public and private side to make it seem like it's an automated transfer (like putting a file in Dropbox on the public and then seeing it show up on the private side), but in reality you have a security guard making sure nobody's copying up `MSOfficeOfficialThisTime.msi`.