Brute force a password protected PDF using the BeagleBone

The biggest benefit to using the BeagleBone is it’s 700 MHz ARM processor. If you’re just messing around with basic I/O that power is going unused, but [Nuno Alves] is taking advantage of its power. He built a PDF password cracker based on the $85 development board.

We recently saw how easy it is to perform basic I/O using the BeagleBone. Those techniques are in play here, used to drive a character LCD and sample a button input from the breadboard circuit. [Nuno] even published separate posts for each of these peripheral features.

The password protected PDF file is passed to the device on a thumb drive. Since the BeagleBone is running embedded Linux you don’t need to mess around with figuring out how to read from the device. A click of the button starts the process. Currently the code just uses a brute force attack which can test more than 6000 four-character passwords per second.  This is quite slow for any password more than four or five characters long, but [Nuno] does mention the possibility of running several ARM processors in parallel, or using a dictionary (or rainbow table) to speed things up. Either way it’s an interesting project to try on the hardware. You can see his video demo of the device after the break.

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