Hide files in JPEG images

The Tech Tray weblog has posted a tutorial for hiding secret files inside JPEG images using the popular Windows archiver, WinRAR, and a little command line magic.

Basically, you create a .rar archive of your to-be-hidden file, then run a copy command from the Windows command line (with the /b binary switch) to embed your secret file in your image. After you complete the process, you can open and view the JPEG like any other image - the only thing that might tip off that the image has got a secret is a potentially bloated file size. To grab the secret file, you just use WinRAR to extract the file from the image.

It may sound like a lot of work, but it's a pretty simple process (watch the video to see how easy it is). This is a neat trick, but if you want to get really serious about encryption, you'll want to encrypt your data with TrueCrypt. — Adam Pash

How to hide files in JPEG's [thetechtray.net]

Saturday, February 24, 2007

Hiding Files in Jpg's

Introduction

Here is a tutorial on how to hide files in Jpg's. Please note it isn't the most secure method, because the information is stored in plain text but it's still cool to play with. A simple solution to make this more secure, is to use encryption on the RAR file when your create it, but thats not the point of this tutorial :) The idea is to show how files can be 'slammed' together, to stop the average PC user from finding them.

Video Tutorial

Please click here to see the video tutorial.

Step by Step Instructions

You will need the following..

• Windows 2000 / XP (probably Vista, too!)
• Basic Knowledge of the Command Prompt
• WinRar

1. Gather your image and the files you wish to lodge into it. Here I have a meeting.txt which which I will slap inside my secret.jpg

2. Add the files you want to hide into a new RAR archive
3. Open Command Prompt

4. Go to the folder where your files are located, in this case 'C:\hidden'
5. Type 'copy /b secret.jpg + meeting.txt.rar lizard.jpg' where secret.jpg is the original picture, meeting.txt.rar is the file to be hidden, and lizard.jpg is the file which contains both.
6. Test the JPG by opening it, and verifying it still opens. If it does, try opening the file with WinRar!

7. The completed RAR file!
8. Here is the image I created when making this tutorial!

Further Reading

• Further reading on steganography
• Wikipedia article on the rar file format