The time comes to just about everyone when a password to PDF file is forgotten or misplaced. If you think you are in deep trouble you may be right, according to one PDF password recovery manufacturer.
They state “Guaranteed recovery for 40-bit encryption…” This leaves you to draw the conclusion that some passwords may not be recoverable if the encryption is higher than 40-bit. This same manufacturer also states that some password recovery may take several days. So don’t expect being able to display that password-protected PDF at your department meeting in front of your boss.
So if you have a robust password, I wouldn’t count on recovering the “open” password for a PDF in a few minutes, unless you have a supercomputer that can attack the problem with your own software. The silver lining to this dark cloud is that people generally do not use strong passwords.
Most password cracking programs use three methods: brute-force, dictionary, and mask attacks. Some have also developed their own proprietary methods and algorithms.
We have looked at a few PDF password cracking programs and have listed the features and prices for you comparison.
Manufacturer: Parallel Password Recovery
Product: Parallel Password Recovery PDF Module
Local Dual Version – $29.00
Support for 2 cores or processors
Local Quad Version – $39.00
Support for 4 cores or processors and 1 NVIDIA GPU
Local Pro Version – $99.99
Supports 8 cores or processors and up to 8 GPUs. Up to 8 clients supported.
Manufacturer: ElcomSoft Protective Software
Product: Advanced PDF Password Recovery
Standard Edition – $49.00
Supports up to 256-bit encryption. Can remove print and other restrictions on protected PDFs. Decrypt PDF only if “open” password is known. By the description one should seriously consider getting the Professional Edition instead of the Standard Edition.
Professional Edition – $99.00
Brute-force and dictionary password processing. Guaranteed recovery for 40-bit encryption only and may take several days to achieve this. Multi-core and NVIDIA card support used for 256-bit encrypted PDFs. Removal of digital signatures, Jscript code and form fields.
Enterprise Edition – $399.00
Guaranteed recovery for 40-bit encryption using Thunder tables which takes several minutes.
This company appears to spell everything out on their program features and capabilities
Manufacturer: Stellar Data Recovery
Product: Stellar Phoenix PDF Password Recovery
Single User (Home User / SOHO Segment) – $29.00
Supports all encryption levels. Provides detailed log reports. Recovers “open” password and then removes all security permissions.
Manufacturer: Top Password Software
Product: PDF Password Recovery – $19.95
This software says it has a 100% recovery rate. It also claims it supports PDF files created by any program. At just $19.95, it is the least expensive of these programs and is worth a try.
As with all products that you may wish to buy, please use this information as a starting point in your own investigation.
Safecracker photograph via Flickr by ktylerconk