Calibre, dropbox, & library encryption

[Beanxx]

Dear Folk--
I work from home, and my home computers are also my work computers. Moreover, I have just one library, containing both my personal and my work related books. Sometimes I need or want to allow people -- clients, students -- to use these machines. Usually this is not a problem, but I have faced some mildly embarrassing situations where a computer repair person is uncomfortable with filenames they see, or where a Desktop search on some innocuous term brings up some racy material in my library.

I keep my libraries in sync across, currently, five devices by keeping my library in a Dropbox folder and accessing it on Android with Calibre Companion, which is less capable than Calibre but a lot easier to use. Dropbox advises you not to do this, but I have learned that this arrangement works fine so long as you _always_ pause sync before you open your Calibre library and make any change, however small. I accrued a lot of strange blips and lacunae before figured this out. But after unscrambling this egg, I have maintained a now-up-to-8,000-volume library for eight years in this way without a glitch.

So I would like to split my library in two, with my main library open and searchable by Windows and other programs, and a personal library that is password protected and searchable only by Calibre and Calibre Companion, or only after opening it with a password.


My question: Is there a way to do this?
Subsidiary question: Would it suffice merely to use Dropbox's password protection on the folder containing the personal library?

Dropbox claims that it encrypts its contents and decrypts them only locally. I am dubious about this. If true, the decryption is so seamless that Windows desktop search indexing sees right through it. But none of my Dropbox folders are currently password protected, and Dropbox claims that its encryption prevents anyone without the password from seeing the files. If this is true (and a have a parallel question in over at Dropbox, where I expect them to answer that I should not be putting a database in Dropbox), then it would be very nice if I could simply put my personal library in a password-protected Dropbox folder, and, once the password is given, could switch to the library in that folder in the usual way and access it with Calibre or Calibre Companion. But I made so many headaches for myself from Calibre/Dropbox interactions before I learned not to access my library with sync active, that I am hesitant to do this unless someone knowledgeable can assure me that this procedure doesn't pose a much greater risk to my library's integrity than what I am doing now. I would rather not set up a Windows encrypted volume for just this (relatively small) library, and I have no confidence that I could access it with Calibre Companion if I did.

Alternatively, if there is a better way of achieving the security I describe above without requiring more technical knowledge than I have, I'd be happy to do that instead.

Any & all help gratefully accepted. --Beanxx

[Deskisamess]

my home computers are also my work computers.

Such a bad idea, for many reasons. Work computers etc. should be totally separate. For more reasons than just social embarrassment.