What is a secured PDF file?
A secured PDF file simply refers to a PDF file that has been protected by a piece of software.
However, the security of PDF files grouped under this banner can vary wildly depending on the solution used to protect them.
Why would I want to secure my PDF documents?
There are many reasons why you would want to secure your PDF documents using PDF file security. The main reason, however, is that you need protection for your PDF documents beyond what encryption provides.
This is likely because you want to have some control over your PDF documents once they have been decrypted (for example, whether a recipient can copy text from your document). This can be because the document contains privileged information or you are selling information that you do not want to be distributed for free.
How can I secure my PDF documents?
At the basic level, you could use a product like Adobe Acrobat. However, it is wise to remember that there are freely available Internet tools that can remove the copy controls you have applied in seconds. This is also true of other secure PDF products that use passwords or plugins to Adobe Acrobat.
If you are serious about protecting your documents, then you will probably want to purchase a PDF file security product that is not password-based – read PDF password protection to see why – and uses US Government strength encryption.
Download PDF file security software that uses US Government strength encryption, digital rights management controls, and does not use either passwords or plug-ins to secure your PDF documents.
Can you secure PDF files for free?
It depends on what you consider ‘secure’.
While you can password lock a PDF with an online tool for free, it’s trivial to remove the security from the PDF file again. It’s unlikely that you will find a free solution that is able to effectively protect documents.
How to remove security from a PDF file
As mentioned, the password protection used in Adobe Acrobat is not a good way to secure PDFs. Flaws in the Adobe Security handler make it completely trivial to edit a secured PDF file – as we’ll show you below.
Here’s how easy it is to edit a secured PDF file from Adobe:
- Upload the document to an online password remover tool
- Enter the open password
- Wait for the website to strip the permissions password
- Download the modified PDF and edit it in any PDF editing software

If the user does not have the PDF open password, it doesn’t mean they can’t remove the protection – just that they need to crack the open password first. This can be time-consuming, but it’s still entirely possible with a PDF security removal tool.
Locklizard Safeguard DRM cannot be bypassed using these tools. It does not use passwords and its permissions aren’t based on an honor system. Instead, a combination of strong encryption, a secure viewer application, DRM controls, and a transparent licensing system keep your PDF files safe.
Is it safe to secure a PDF online?
Some PDF security applications enable you to protect PDF files online on a cloud server (securing PDF files in the cloud).
Most of these programs, however, only provide standard PDF password protection. The other major disadvantage of this approach is that you have to upload unprotected PDF files to a cloud server where they could be easily compromized.
A much more secure way of securing PDF files is to do so on your local computer (offline), and then distribute the encrypted files online. This ensures both your unprotected and secure PDFs are always under your control.
How to print a PDF file that is secured
Printing a secured PDF file that has been protected using a password, is just as easy as editing one.
You can use the method above to strip print and editing protections, or open it in an editing program that doesn’t honor Adobe’s permissions, such as Word, Google Docs, or a Mac PDF editor. Users can print straight to a file too, creating an identical copy of the PDF with no controls applied.
How to copy from a secured PDF file
There are various ways to copy from a secured PDF file, provided it has been protected with an ineffective tool like Adobe Acrobat or an online PDF password protector.
The first and easiest method is to upload the document to an PDF password removal program or website. This will strip Adobe’s permissions and allow you to do whatever you wish with the document, including copying and pasting.
If printing is enabled, you could instead drag and drop the PDF into a Chrome browser window, press the print icon, then print it to a PDF. This will create a version without the copy/paste restrictions. Alternatively, you can upload it to Google Drive and open it in Google Docs.
Finally, if none of that works, you still have the option of screenshotting the document and uploading the image to an OCR recognition site. The site will convert the image of the text into real characters that you can copy and paste.
Can you comment on a secured PDF file?
Locklizard Safeguard DRM lets you comment on and highlight a PDF file even if it has been protected. Unlike Adobe Acrobat, it does so without compromising the document’s security.
Further reading on PDF Security
To learn more about the PDF security, read the following white papers.
PDF Security and Encryption
How Secure is Adobe PDF Security?
Also see PDF Security Issues which covers flaws and cracks in various PDF Security implementations.