Is this a secure way to use LibreOffice (or Microsoft)?

For Microsoft, I’m only interested in the standalone versions of Word & Excel. In my country there is an option for this as you can see on this page
So, there are no future updates, you buy a version of these products permanently.
Let’s say in my case I only use a USB + a cloud storage service as backup/protection for my files. Like a secure Kingston USB + NordLocker (Also a good one I think?).
Would it make sense to install Word & Excel only on the USB so if there are temporary files, these are already encrypted because of the password protected USB?
I will also encrypt the original files so they are actually double encrypted now.
Did I miss something or does this look secure to you?
I used Microsoft as an example but I can also do this with LibreOffice.

FYI: The Link you provided seems to be broken.


i am not sure what you mean by “use in a secue way”

  1. Do you want to proect your enviroment (OS) from manipulation by potentially malicious documents/files?
  2. Do you want to protect your Office installation from beeing tampered with?
  3. Do you want to protect your created / modifed documents/files?
  4. Somethimg else ?

I guess, on way would be to run LO in a isolated process, container (docker,lxc) or a Virtual Machine.
And store the files either with password protection or on an encrypted storage/mount.

If you must / want to use any cloud storage, make sure you only upload strongly enctrpedy files/data … and keep the encryptoin key to yourself.

Hope it helps.

Hi. Thank you for quick response and help.

I’ll be more specific so you can understand my ‘problem’ better:

  • Let’s say I don’t use any cloud storage (so I only have a secure USB).


  • I create a sensitive document with either LibreOffice or Microsoft.

  • I encrypt the document with a password & save it on my USB.

  • Would it be better to have LibreOffice/Word&Excel installed on my USB so no potential backups/temporary files can be found somewhere on my pc without me knowing? Or it is also possible to install it on my pc?

So I have 2 main questions:

  • Are there some copies made of my document without me knowing?
  • If the USB in this example stays in my hands is there a possibility that LibreOffice/Microsoft still has my data of my document somewhere stored or is this impossible?
  1. Are there copies made of my document without me knowing?

My Answer for Libreoffice …
… , i am not a LO developer, so … please keep in mind, i might be … wrong
Furthermore … my answer might not fit to all LO Versions.

But, as far as i know LO stores

  1. Files where you explicitly tells it to, (manual and auto saves)
  2. In Temporary Directory (which you can specify yourself in Options → Paths )
  3. And maybe … in the Backup Directoy if you enabled backups (But … these mirgh also only be for user settings)
  4. No Copies should be stored or send anywhere if you did not specify it yourself.

If you use the portalbe version of LO i.e.

My Answer for Microsoft Office …

I would say there is not way to be sure.
Office has a very trackrecord of sending UserData to MS Servers.
And handling metadata poor/insufficent-ly.

if you want to be sure, you could run Office on disconnected machine or a VM to be sure it does not do anything suspicious.

Regarding where it stores Temporary files: I would guess in some Windows Temp dir but honestly i have no idea, sorry.

Hope it helps.

Thanks! So you would prefer to just install it on your computer? If I disable a couple of these temporary/backup options (or knowing the locations would also be fine) I’m good I think? Thanks!

I would check the LO settings fo the portable version and see if these are sane/secure.
If they are, i would just use it. If not and you have to modify it anyway, you could just as well use the normal installation and modify its settings and use that.

Hope you find something that works for you.