As part of your business operations, you likely have to share PDF files that contain important or confidential information and so would naturally want to prevent the wrong people from becoming privy to your confidential information. Since Adobe Acrobat (and Acrobat Reader) is generally used to view, create, print, and manage files in PDF format, many also tend to rely on it to provide security solutions. Yet, Adobe Acrobat only offers basic PDF security measures and its drawbacks make it unsuitable for enhanced security.
Problems with Adobe Acrobat
There are two types of passwords for password protecting your PDFs with Adobe Acrobat:
- The document open password which is required to open the PDF
- The permissions password which is required to enable or disable PDF restrictions
You have to share the document open password to allow users to open the PDF. Yet, once the user gets hold of the document open password, he or she can easily change the permissions password and disable the restrictions that you imposed on copying and pasting, editing or printing. This basically means that users can do what they like with your documents. So, why even bother to password-protect your documents with Adobe Acrobat?
Another problem with Adobe Acrobat passwords is that they can be shared easily. It is also very easy to remove the password with password removal software – just Google this to see for yourself.
Furthermore, the protection mechanisms offered by Adobe Acrobat are not necessarily implemented by non-Adobe readers. For example, if you have disabled printing in Acrobat, the same restrictions won’t necessarily apply if the file is opened in a non-Adobe PDF reader.
The choice of security controls that can be applied using Adobe Acrobat is also rather limited and takes no account of the destination environment of the user. For instance, it does not consider the location in which the PDF is accessed or from what device.
Alternatives to Adobe Acrobat
Strong encryption, DRM controls, public key technology, and licensing controls are all effective alternatives to Adobe Acrobat PDF security. PDF security products often offer them in combination to deliver better security.
The use of strong encryption will prevent unauthorized users from accessing your PDF files or making copies of them. So, people might still copy your files, as it is impossible to prevent them from doing so, but they won’t be able to access them without the decryption key.
The most widely used secure encryption algorithm for PDF encryption is 256-bit AES (US Government strength).
Public Key Technology
measure is used to:
- Protect the decryption key required to access the PDF, preventing unauthorized users from finding it, and
- Create a digital signature that confirms that the PDF document has not been altered and verifies the sender.
It is much more secure than Adobe Acrobat password protection as the key is not exposed to the user and cannot be attacked – the key is securely sent to an authorized user’s device and held encrypted in a key store for future use. By using secret keys, there are no passwords to manage which users might forget or pass on to others.
Licensing controls enable you to apply restrictions that are unique to each user. For example, you can allow one user to make prints of a PDF document while disallowing another user from doing the same with the same document. You can also revoke access to a particular PDF document on an individual user basis or for all users. In addition, you can lock PDF documents to specific user devices and log document use for specific users.
DRM controls enforce what an authorized user can do with a PDF document. Such controls enable you to:
- Stop copying and pasting
- Stop editing or modifying
- Stop or limit printing
- Stop screen grabbing
- Revoke PDF files no matter where they are located
- Expire PDF files after a certain length of time
Unlike Adobe permissions, it is difficult to remove DRM controls since they are part of the protected PDF document and are enforced by secure PDF Viewer software.
In the digital world, you need to be able to control what can be done with your PDF files once they are sent out. With Adobe Acrobat, it is up to the users whether they want to respect your intent of protecting your PDF documents. A PDF DRM security product on the other hand actually gives you complete control over your PDF documents.