Which tool to encrypt existing PDF file [solved]

[Moltke]

Hi.
Does anyone know a tool to put encrypt/putting passwords on existing PDF files? Both gui tool and non-gui tool work for me.
Normally my PDF files is generated either by the built-in pdf printer in Linux, or by export from Inkscape.

Hi [member=6945]Sprintrdriver[/member]  In LL you have two methods at your disposal:
1.- You can use LibreOffice for this; In LibreOffice, click on file menu and open  the pdf file you want to encrypt, again,  from file menu choose “Export as PDF” option and navigate to the “Security” tab. There you will find the “Set Passwords” buttons that will let you set a password for opening the file, or/and a password for editing permission. After setting the passwords, you can click the “Export” button and you are done.
2. - You can use gpg tool.

Code:

gpg -c some file.pdf

you'll be asked to type a password, type it in and hit enter. confirm the password, hit enter again and that's it. For decrypting the file you do

Code:

gpg some file.pdf.gpg

if by any chance, the original file is in the same folder you'll have to remove it before decrypting.

Hope this helps!