PDF Security
PDF is the most popular format for distributing reports, ebooks and other document files in a cross-platform manner. One of the benefits of this format are the granular security settings it lets you set for your files. In this post you’ll find an overview of these features.
What do we mean by “security”? Generally there are three types of document security (at least as far as PDFs are concerned) - authenticity verification, access control and copyright protections. Lets look at all three in turn.
First, PDF supports digital signatures that let you ensure that the file was created by who you think it was. This is immensely useful when dealing with important documents and sensitive data. The signature doesn’t forbid the viewers ability to interact with the file - it only lets them ensure they’ve got the real thing. However, this type of security is rarely used by the average user.
Access control means specifying who is allowed to open the document, how many times a .pdf can be opened, etc. This feature can be very restrictive - for example, a document that is protected by a password can’t be easily converted to Word. For access control, there are passwords and certificates. A password can either be used to restrict editing, or both editing and viewing. Certificates serve the same ends, but instead of a password that must be remembered there is a certificate file that the user employs for authorization.
The third and final type of PDF security features is copying permissions. These determine which parts, if any, you can print, copy or extract from the PDF. For example, you could create a document that can be viewed by anyone (no password), but that is protected from plagiarists and scrapers by a restriction that makes it impossible to extract content. However, note that a decent pdf to word converter might be able to copy the file anyway. The protection is somewhat illusory in any case because anything that can be seen on the screen can (by design) be “copied” with a simple screenshot and some OCR tools.
Overall PDF is a very secure document format, but be careful about what security features you pick for your files - some security settings may be an overkill and inconvevience to the end user, while other’s may offer only an illusion of safety.
