What Operating System are you using? If it is UNIX/Linux, much of what you want to do can be accomplished using the file "Access Rights" found in the "Advanced FIle Functions" part of File I/O. Under MAC O/S you have some of the capability, under Windows, next to none (what else is new!). None of these, strictly speaking, will password protect your file, although under UNIX/Linux you have that effect, as if the permissions are set to "owner only" for the read and write, you will have to log on as the owner to read or write. To make the files do this in Windows would require encrypting them and decrypting them, using another program, which could be written in LabVIEW. The description of file permissions is given in the LabVIEW Help, accessible while in LabVIEW under 'Help', "VI, Function & How To Help ...", search using 'permissions'.
P.M.
PutnamCertified LabVIEW Developer
Senior Test Engineer North Shore Technology, Inc.
Currently using LV 2012-LabVIEW 2018, RT8.5

LabVIEW Champion