There are a number of PDF password remover tools that are easily available on the Internet in order to access lost passwords. Here, it is important to mention that PDF password protection remover tools were initially invented to be used only under appropriate circumstances – that is only if the original creator of the PDF file has lost the password and if the user has the legal right to view and modify the PDF but does not have the password. However as with all applications their use was quickly misused for gaining access to files by unauthorized users and/or removing PDF restrictions.
One might ask how PDF password remover tools came to be so effective? This article provides a clue – How Adobe encrypts PDF files – “Adobe’s PDF protection scheme is a classic example of security through obscurity. They encrypt the content of a PDF file and hope that no one figures out how to decrypt it.”
Not only are PDF password remover programs highly effective in easily decrypting PDF files, but many of them are available for free. They use various methods to remove PDF passwords such as dictionary attacks – basically they have a massive dictionary of popular and common passwords, and they will try all of them to see if any work. The process takes maybe a few minutes to run through thousands of these. Typical passwords NOT to use include: 123456, 123456789, password,. admin, 12345678, qwerty, 1234567, 111111, photoshop, 123123, 1234567890, 000000, abc123, 1234, adobe1, macromedia, azerty, iloveyou, aaaaaa, 654321, fred. If you want to share PDF files securely then using obvious passwords is not going to provide much protection.