With a PDF viewer or “open” password, you’ll have to perform a more complex brute force, key search, or dictionary attack on the password. If you don’t, however, it’s still possible to open the PDF. The easiest way, naturally, is to enter the password, provided you know it. Let’s start by showing how you can open a password-protected PDF that has a viewing password applied. Once you’re happy with your password, click “Apply”. As we’ll soon demonstrate, this won’t stop it from being removed, but it will eliminate one avenue of attack. To avoid brute force attacks, you should use a strong password to protect PDF files – your password should be long, contain numbers and symbols and avoid words, phrases, names, and dates. Protecting a PDF with a password using Adobe Acrobat

Select “Viewing” or “Editing” and enter a secure password.

Click “Protect Using Password” in the top bar.

Open your PDF in Acrobat and press the “Protect” button in the sidebar.

If you insist on using it, though, here’s how: Though all work on more or less the same principles, Adobe Acrobat’s prevalence in the enterprise has made it the tool of choice for many.Īs we mentioned earlier and will soon demonstrate, the security provided by Acrobat and other PDF Editors is greatly flawed and can be trivially removed. There are dozens of freely available tools available to password protect a PDF, but the most commonly used is Adobe Acrobat. How to password protect a PDF with Adobe Acrobat We’ll then propose an alternate stronger solution to passwords that will better protect your PDF documents. Today we’ll be demonstrating these security flaws by showing how to create and open a password-protected PDF, as well as how to print it. This security weakness is taken advantage of by Elcomsoft’s PDF password removal software among others. Though Adobe has updated its encryption algorithms and key lengths several times, fundamental flaws exist in its password-based implementation.

For better or for worse, the security mechanism has persisted since.

Just four years later however it was cracked by a Russian security engineer working for Elcomsoft. The password and encryption combination became immediately popular, and understandably so it was all businesses had at the time. It wasn’t until 1996 that Adobe released a version that included passwords, and a few years later digital signatures and RC4 encryption. As such, on its release in 1993, the Adobe PDF format didn’t ship with any form of PDF protection. When PDFs were developed in the 1990s, the priority wasn’t security – it was on making the document format as shareable as possible. Below we cover how to password protect PDF files, and the ways that users can easily remove that protection. Some might argue that password protecting PDF files has its uses, but protecting confidential and sensitive business information is not one of them.

How to password protect pdf free mac