Steganograohy on the Go: Hiding TrueCrypt Volumes in Movie Files
Crossing borders with sensitive information can be difficult in areas where information is tightly controlled. We have been playing around with ways to encrypt information and hide it in other content - a form of encrypted steganography. So we tried to encrypt data with Truecrypt, an open source file encryption software, and hide it in a movie file.
Ordinarily, anyone trying to open an encrypted Truecrypt volume found on a computer or thumb drive would receive an error message, making the encrypted files obvious. It just screams that there is something out of the ordinary on a USB thumb drive, SD Card or computer.
We wanted to create a secure volume that fits inside of a video that actually plays -- such as a downloaded YouTube video of cats or family video in mp4 format. Within that video is a hidden TrueCrypt volume.
Below is a step-by-step guide to hiding a TrueCrypt Volume inside of a video. Please be aware that there may be anti-encryption laws in your country, so please educate yourself on local law before proceeding.
Level of difficulty: Moderate
Time to complete: 15-20 Minutes
Tools needed: Computer Running Windows, Linux or Mac OS, Python, Youtube Video or home video in mp4 format, TrueCrypt, Terminal or Command Prompt.
Step 1: Go to Python and download and install the appropriate version for your computer operating system. Follow the instructions on installing Python on your operating system as provided by Python.
Step 2: Go to YouTube, if you want to use a YouTube video, for instance, or use your favorite video of your cats or kids.
Step 2.1: Download a YouTube video (You can use http://www.clipconverter.cc/) or save a video from your mobile phone or camera in mp4 format.
Step 3: Download this Python Script (Right Click and select download file)
Step 4: Download and install TrueCrypt.
Step 5: Create a volume in TrueCrypt. We show you below how that is done.
Step 5.1: Open TrueCrypt and click "Create Volume."
Step 5.2: Select "Create as encrypted file container" then click next.
Step 5.3: Select Hidden TrueCrypt Volume and Click Next
Step 5.4: Select file location where the file will be saved by clicking "Select File"
Step 5.5: Type in file name with “.mp4” file extension at the end and then click save.
Step 5.6: Follow prompts through "outer volume encryption." Set volume size in MB or GB. Your volume size must be smaller than the size of the portable storage device you wish to store it on. The screenshots below are in order from left to right and down illustrating the process of creating the truecrypt volume.
Step 5.7: Create a hidden volume by following the prompts. (Volume size must be smaller than outer volume. i.e. if you chose to make your outer volume 2GB your inner volumen should be less than 2GB.) The screenshots below are in order from left to right and down illustrating the process of creating the truecrypt volume.
You have successfully completed a TrueCrypt volume. Here is how to embed it into into a video file.
Step 6: Open a Command Prompt or Terminal window on your computer.
Step 6.1: Type in this command to embed:
python /location of python script file downloaded/ tcteg2.py /location of video file/video.mp4 /location of TrueCrypt volume created/ TrueCryptVolume.mp4
Step 6.2: Click enter and the embedded volume will be created:
Step 7: Click on your created volume to view the video or mount the volume using TrueCrypt to begin adding files.
It is important to note that this is not a foolproof method to the trained eye. An individual who examines the file size in relation to the video length might be suspicious. However, this does provide you with a working video file that conceals a TrueCrypt volume. Again, be aware of any laws prohibiting using or transmitting digitally encrypted information.