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.

If you ever forget the password for any important pdf files, you'll need to use a utility that can either remove or unlock the password. However, some programs may not give you the desired results. You can grab a trial version of some of these if you wish to check them out. Sadly though, some of these trial versions are "crippleware", and can only decrypt the first part of a document. A frequent concern on the user comment section for one of these programs is that it's hard to know if the program will function as it's supposed to when it's crippled in this manner. (Also, should you decide to test these utilities, be sure to download them from a site with a good reputation for security, and perform a virus-scan on the program file before installing it.)

Here are a pair of pdf password utilities that will run under Windows.

Using the GuaPDF Program

GuaPDF is a budget-priced password-cracker program from a group that calls itself the "Russian Password Crackers". Their website states that GuaPDF will delete the user restrictions password, even if 256-bit AES encryption has been used. However, it's doubtful that you'd be able to use it to open any encrypted documents. It can only work with up to 40-bit encryption, while modern pdf creator programs will use 128-bit encryption by default. Attempting to open a file with 128-bit encryption will pop up an error-message box, which will direct you to the website for the Parallel Password Recovery program.

The free demo version is "crippleware", so you can't use it for large files.

The Parallel Password Recovery Utility (PPR)

This utility has features that GuaPDF doesn't have, but it can be a tad-bit more complex to use. (Thankfully, though, on-line help is there if you need it.) In addition to performing brute-force attacks, PPR can also perform dictionary and misspelled password attacks. You'll need to hand-edit the password definitions file so that PPR will know which method to use, and which character set to use. Its ability to utilize GPUs and multi-core processors can increase processing speed. It's designed to crack 256-bit owner passwords. There are several different versions, depending on your budget, and how many CPU cores that you'd like to utilize.

You'll want to be aware, though, that you can only use PPR to crack the owner password. It can't delete the password that sets restrictions on the user, and won't even work with a file if no owner password has been set.

The trial version of PPR is fully operational, except that it will only break passwords with five or fewer characters, and it can only be used on a local workstation with up to four processor cores.