Is PDF password protection secure?
Even today, most people are of the opinion that PDF password protection helps to keep their PDF data secure and safe. However, this is not entirely true.
Almost every PDF application builds PDF password protection functionality into their software that provides a quick and easy security option for users. But experts recommend that this feature should not be widely used, especially to safeguard confidential information. Since protecting PDF files with the help of passwords is much better than not doing so, why is it that PDF password protection is not such a good idea? There are a number of aspects that determine how safe such “PDF password protected” files really are.
The fact that confidential data in a PDF document hinges on the secrecy of a single password, is in itself a dangerous notion. If a malicious user or hacker gains knowledge of the password or employs external applications to break open into the PDF password security, they can gain easy access to the resources controlled by this password. It is widely acknowledged that most users reuse old passwords and create weak ones which in itself are the weakest links in password controls. In addition, if an authorized user is given the password to open the PDF document then there is nothing preventing him/her from sharing the password with others – so security here is really a matter of trust.
Although passwords have been the most common form of security measures by which users prove their identity to a PDF file, it has also been the most vulnerable. One of the main reasons why password-based authentication in PDF files has become so common and widespread is not because of the security that it offers but because of the ease of use, low cost, simplicity and practicality.
A PDF file that is dependent on a password-based authentication relies on a single word for security; this in itself is a significant vulnerability. An attacker who gains knowledge of the password can completely compromise the security of the PDF file, removing the security and making it available to others without the need to enter a password (or the password could just as easily be published along with the file).
A malicious user or hacker has the ability of mounting numerous attacks on a password authentication system in a PDF document. These include: attacks on the system end, which is targeted at the passwords stored in the PDF document; attacks on the channel of communication through which passwords are transmitted such as BYOD devices, media and other protocols which connect the system to the user; and attacks on the user end, targeted directly at the user.
Of all the three forms of attacks, attacks on the user end are considered the most serious as such attacks require very basic technical or specialist knowledge, but ensure a very high chance of success. Studies reveal that users often make a note of their passwords and place them in visible locations while some others build extremely weak passwords based on simple dictionary words or personal data, which can be easily deduced by people who know enough about them.
Whilst most ‘hackers’ tend to obtain passwords by exploiting users than by using technical methods, password protected PDF documents can be easily exploited by password cracking tools due to the reliance on weak passwords and insecure security mechanisms.
If your documents require a stronger level of security than simple PDF password protection then try PDF DRM companies such as Locklizard to protect your PDF files. Locklizard uses public key technology to protect your PDF files against unauthorized sharing (PDF files are locked to individual computers to prevent distribution), modifying and printing. And it uses DRM controls to enforce document expiry, enable document revocation, apply document watermarking, and prevent the use of screen grabbers.