a good habit to encrypt file

By the way, habit to set up password to encrypt office file

You have noticed that window property has encryption attribute and this is the second encryption of the file by office. 

Now you have to think you have to ensure no keylogger and clean computer. Previous post i had already taught to use gpedit to allow specific application. And disconnect network. Theoretically this should be safe.

But you will start to notice your computer monitor and the TV and mobile device near computer. This is only the beginning.