Portable Document Format Security
PDF is the most popular format for downloading reports, ebooks and other document files in a cross-platform manner. One of the niceties of this format are the fine-grained security settings it lets you set for your documents. In this post you’ll find an overview of these features.
What does security mean here? Generally there are three types of document security (at least as far as PDFs are concerned) – authenticity verification, access control and copying settings. Lets examine 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 official reports and sensitive data. The signature doesn’t forbid the viewers ability to interact with the document – 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 view the document, how many times a .pdf can be viewed, and so on. 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 online converter might be able to copy the document anyway. The security is a bit exaggerated in any case because anything that can be viewed on the screen can (by design) be “copied” with a simple screenshot and some OCR software.
Overall PDF is a very secure document format, but be careful about what security features you pick for your files – some protection types may be an overkill and inconvevience to the end user, while other’s may offer only an illusion of safety.
This entry was posted on Wednesday, January 28th, 2009 at 7:26 am and is filed under General. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.