PDFKey Pro

Locking files with a password can prevent unauthorized persons from reading or modifying them. If you need to show your work, in PDF format, to someone, but you are afraid he/she will attempt to steal it, you can use PDFKey Pro to restrict certain functions or lock your documents completely. The application lets you choose from three different encryption algorithms, according to your desired security level.

You can download the 1.85 Mb setup file rapidly and use it to install the software without any complications. You will need the Java runtime environment to run PDFKey Pro successfully. If you do not have it, the setup wizard will download and install it automatically.

PDFKey Pro's compact interface consists of two large icons. One of them will lock PDF files, while the other unlocks them. You can either click them and browse for one or more PDF documents or drag and drop them over one of the icons. When locking files, a small window will appear on the screen, where you can type a password and select a security level from a drop menu. If you type a second password, on the right half of the window, you can prevent copying, printing or editing the file's contents.

Encrypted PDF documents are saved as separate files, with different names. Alternatively, you may set PDFKey Pro to rename the original file, instead of the encrypted one, prompt you for a destination folder or save the encrypted file in a folder of your choosing at all times. To unlock one or more PDF files, you need to perform the same task, using the Unlock icon. After you type your password, you will be able to access and edit them as usual.

Pros:
Besides locking PDF documents, the software can also prevent actions like printing or modifying contents. PDFKey Pro's interface is compact and very easy to use. You can lock or unlock files by clicking and dragging them over the appropriate icon.

Cons:
The software's options do not include deleting the original PDF files.

Protecting PDF documents is an easy and straightforward task, thanks to PDFKey Pro. Its functions are straightforward and they can be used even by inexperienced users.