Windows 10, 8.1, 8, 7, Vista, 2003 and XP. Including both 32-bit and 64-bit versions
With Free PDF Protector 4dots
you can batch protect many PDF documents with passwords
It is absolutely free, very easy to use and also multilingual
You can set both a user password (used for opening the PDF documents) and an owner password (used for settings various permissions such as content copying, commenting,
printing, form field fill-in e.t.c.)
with PDF documents and their subfolders can be protected
The PDF documents can be protected with 128 bits or 40 bits encryption passwords.
You can protect PDF documents simply with a right click in Windows Explorer
since Free PDF Protector 4dots can be integrated into Windows Explorer.
Also, you can just drag and drop PDF documents
to be protected to the main window of the application.
A text list file of PDF documents can be imported
The application does NOT need Adobe Acrobat software installed
With Free PDF Protector 4dots you can also batch set metadata
of PDF documents such as author, subject, title, keywords, creation date e.t.c.
It can also be executed from the command line, which is useful for inclusion in scripts
The application is multilingual and translated into 38 languages