Utilities That Will Remove Pdf Password
When creating pdf files, you have the ability to set two different passwords. If you set the “owner” password, the file will be encrypted. This will prevent unauthorized persons form opening it. Assigning a password for “user restrictions” allows you to control how a person can use the file after it’s been opened. This will prevent someone from being able to print a file, to change a file, or to copy content from the document into the operating system’s clipboard. On occasion, though, you might need to remove pdf password.
In case you’ve lost the password for an important document, there are several utilities available that can either crack or remove a pdf password. However, you may not always get the results that you want with them. You can download trial versions of some of these utilities if you wish to try them out. However, some of these demos are crippled, and will only decrypt part of a document. A common complaint on the forum for one of these programs is that it’s hard to prove that the program will do what the user needs to do when its functionality is crippled in this manner. (Also, if you do download any of these utilities, be sure to download from a reputable site, and virus-check the program before you install it.)
Here are a pair of pdf password utilities that will run under Windows.
Using the GuaPDF Program
GuaPDF is a low-cost utility from the “Russian Password Crackers”. According to its website, it will remove the user restrictions password, even if 256-bit AES encryption is used. However, you most likely won’t be able to use it to open an encrypted document. It’ll only work with up to 40-bit encryption, while the default for most current pdf creation programs is to use 128-bit encryption. Trying to open a file with 128-bit encryption will pop up a dialog box, telling you to visit another website to try the Parallel Password Recovery program.
The free demo version is “crippleware”, so you can’t use it for large files.
The Parallel Password Recovery Program (PPR) Utility
This utility has more features than GuaPDF, but is a bit more complicated to use. (On-line help is available, though.) In addition to the brute force method that GuaPDF uses, PPR can also use the dictionary attack and the misspelled password attack methods. You’ll need to configure the password definitions file to tell PPR what method to use, and what character set to use. PPR can take advantage of both multiple-core processors and GPUs. It’s designed to crack 256-bit owner passwords. Several versions are available, depending on how much you’re willing to spend, and how many processor cores that you’d like the program to use.
Note, however, that PPR can only work with the owner password. It’s not designed to remove the password for user restrictions, and won’t work with a file if the owner password isn’t set.
The demo program for PPR is fully functional, except that you can only use it to crack up to a five-character password, and it will only work on a local computer with up to four processor cores.