Anything you do to encrypt can beundone eventually.
Best way is to encrypt your data yourself and limit access to your computer and encrypt your hard drive(s)
My newest laptop has a fingerprint reader, but I know that would only stop someone without a screwdriver or the means to purchase one.
Or you could keep your library on an external device which you only plug in when using it and keep it in the wall safe with your other sensitive information. Might sound facetious but if you are seriously worried a simple method. Nothing is foolproof and mostly I just hope for the best
Helen