Security passwords on PDF files

Last Reviewed: November 10, 2016

Article: DTS0161


Applies to: dtSearch 7


PDF files can have two kinds of passwords:

(1) An "open" password prevents any access to the file unless the user enters a password before opening it in Adobe Reader. 

(2) An "owner" password prevents certain operations (printing, editing, etc.) only.

If a file has an "open" password, dtSearch cannot index or search the file at all and will report the file as inaccessible due to encryption.

If a file has an "owner" password only, then you can open the file in Adobe Reader without entering a password, but you may not be able to print, annotate, modify, or copy text to the clipboard from the PDF file.  Starting with version 7.80, dtSearch can index and search these files if (a) the type of encryption in the file is one of the following:  40-bit RC4, 128-bit RC4, 128-bit AES, and 256-bit AES, and (b) the file permissions do not disable text extraction.  (Earlier versions of dtSearch could only index and search PDF files with 40-bit RC4 encryption.)

To tell what kind of encryption is used in a PDF file, open the PDF file in Adobe Reader or Adobe Acrobat, click File from the top menu, then select Properties and then select the Security tab.  If you select Password Security from the drop-down list, one of the options is "Restrict editing and printing of the document."  If that is selected, and "Enable copying ..." is not selected, then dtSearch products will not access that PDF file.  If a PDF file has these selections, a password is required to change these settings inside Adobe Acrobat.

Developer note: Support for higher-level encryption is implemented in a new component that is subject to export restrictions. Please see the "International Law and Export" section of the dtSearch license.htm file for more information.