Cracking PDF User Passwords Or Editing Encrypted PDF ( Tutorial )

Posted on Feb 22, 2013 by Aneesh Kansal | 6942 Views | 14 min read

PDF has become one of the most popular and widely used file format. Today mostly all the ebooks are available in PDF format. But many times the PDF files are password protected by the creator or the owner. There are two types of password protection for the PDF files. A user password and owner password. The user password doesn’t allow the user to open the file without entering the password and the owner password doesn’t allow the user to print or edit the PDF file. There are many situation where you may find it necessary to crack this passwords like when you forget the user password to your personal PDF file or you may want to edit the file for what so ever reason or you may just want to crack the password because you can. There is no greater delight in computers then cracking of passwords. Here are methods to crack the both user and owner passwords using a software.

Advanced PDF Password Recovery

First you have to download the Advanced PDF Password Recovery software. Here are the links.

DOWNLOAD
DOWNLOAD ( Torrent Link )

CRACKING OWNER PASSWORD
This password is very easy to crack, the above software cracks it instantly and then you are free to edit or print the PDF document. Here is the method.

STEP 1) Start the software and open the document to be cracked in it.

STEP 2) A window will instantly pop out like in the image below

Click on “Decrypt now” button.

STEP 3) The PDF file will be instantly decrypted and it will provide you with the option to save the decrypted document in another location.

CRACKING USER PASSWORD
This password is very hard to crack and it can be done only using methods like Brute force and dictionary attack. But before you start lets have a look at the hurdles in this method. Now everyone knows that brute force is the method where the software tries every combination of letters to guess the correct password and so it can take very long time to guess lengthy passwords. Now PDF files are mostly encrypted using 128 and 256 bit AES encryption i have provided the benchmark results for brute forcing this passwords.

( This benchmarks results were taken on a PC with Celeron 2.2 processor, 1 Gb RAM, with no graphics card. Sorry, my other PC has been sent for repair and i had no choice but to take the results on this lower end PC, if you have a core processor or a graphics card it will surely increase your speed, as the software supports GPU acceleration.)

as you can see the time to crack the password increases exponentially as the length of the password increases.The 256 bit takes less time then 128 and the maximum length of password you may think of cracking is 6. After seeing the above results if you still want to try to crack the password, here is the method

STEP 1)

Start the software. The default setting are brute force attack for 4 letters. If you want you can change the setting and select dictionary attack or increase the length of the password to be cracked.

STEP 2)

Now open the PDF file. A window will pop out, select “recover now” option.

STEP 3)

The process will start and when it finds the password, it will notify you.

Note :- The above software is genuine and there is no legal problems in using it so happy cracking