Using Steganography and Cryptography to Bypass Censorship in Third World Countries
cd /Documents/Now in the /Documents/ directory, we want to create the message we want to Encrypt into an Image. We can do this by imputing the following:
nano message.txtWrite a small test message in the nano editor. Once finished, hit CTR+O and Enter to save and CTR+X to close.The Next step is to create the image that we'll use to hide our encrypted message inside. To do this, we open the Gimp Image Editor. Once opened, we want to click File>New > Advanced options and delete the Gimp Comment finally click >Ok.Now, from somewhere in your system, pick an image to drag and drop it into your Gimp project. After that's done, once again click >FIle> Export As. Export the image to your /Documents/ directory in the .jpg format. I named mine image.jpgThe following step is to embed the file message.txt with our encrypted message into the image we just created in Gimp image.jpg. To do this, we run the following command in the Terminal:
steghide embed -cf image.jpg -ef message.txtYou'll receive the following options:-Enter Password: PasswordToDecryptMessage-Re-Enter Password:PasswordToDecryptMessageAfter hitting Enter, if it all went well, the output should be: "embedding "message.txt" in "image.jpg"... done"You can now open the image to notice that nothing seems different, you can e-mail it, put it on a USB, send it to someone, and the message will stay hidden inside it - until the intended recipient revives it and attempts to open the message with the passphrase set in the embedding process.To extract embedded message.txt from image.jpg, we input the following in the Terminal:
steghide extract -sf image.jpg>Enter Passphrase: DecryptionPASSWORD > Hit Enter:If all goes well, the the output should be: "wrote extracted data to "message.txt"."You can now open message.txt to view the hidden message.
Remember, Steganography and cryptography are strongest when combined. A message sent in secret (steganography) in an encrypted form (cryptography) is much more secure than a "plain text" message sent by secret means or a clearly sent encrypted message. There are some cases in which Steganography can take the place of cryptography. For example, German bans on encrypting radio communications were recently countered by applying Steganography to radio communications [Westfeld06]. Generally, however, Steganography is not intended to replace cryptography but supplement it" [Johnson95]."I hope this information was useful to some. Thank you :)