Using Review tools on a password-protected file

[Dave]

Hello.  I posted this to the okular forum on forum.kde.org and got no
response. That is truly one of the least helpful support forums I've
ever seen. So I'm trying here.

I've been using Okular on Linux for several years and quite like it (I
have version 1.10.1 according to the About dialot). I recently tried to
add highlighting to a PDF, but found the Tools > Review function grayed
out. It seems that the file is password protected, and I suppose that's
the reason why.

Just for kicks I tried Evince, and found that I could add highlighting
using Evince, and save. The highlighting is displayed by Okular, showing
that it has been saved in the file, rather than just remembered
separately by Evince.

I prefer to use Okular, but is there any way for me to get around this
protection to add annotations to the file? Why is this possible in
Evince? Are they failing to respect the protection applied by the
author? Thanks.

Dave