Reply To: How to set a password on InDesign files for OPENING the INDDs?

@Dear Oleh
I tried it and I found interesting thing. When I open the .indd file including the my protected pdf file, InDesign asks me to type/insert the password, in second time I choose “Cancel” button to see what happen and how InDesign reaction to select the “Cancel” button, but the file was opened!?!. I can see the the almost blur layout of everything in my layout. if I choose Zoom (Z) tool and click over the protected frames (the pdfs I placed) their contents were disappeared (the protected frames turn into grey color with a cross lines into it; exactly like you select “Fast Display” command (View > Display Performance > Fast Display).
If value zoom is set to 75% or higher; nothing shows, but less than 74% everything appears and this is thing I don’t like.
Also I select Preferences > Grids > “View Threshold” drop-down menu and changed the value to lowest number that InDesign accepts (5%), but it doesn’t work and everything shows in 74% zoom set again and again?!
Why I choose “Cancel” button; InDesign open the protected file?