What is Steganography?
Steganography is the science of hiding secret message inside another larger and harmless looking message. This is one notch above regular cryptography; which just obscures the original message. Steganography tries to conceal the fact that there is a message in the first place. Steganographic message often appears to be something else than the original (secret) message, like a picture, sound, larger text, etc.
Some terms related to Steganography:
plaintext: The original secret message that needs to be communicated.
ciphertext: Secret message is often first encrypted using traditional methods. Encrypted message is known as ciphertext.
covertext: A larger and harmless looking data which is used as container for the plaintext/ciphertext. This can be a picture, sound, text, etc.
stegotext: The data generated after embedding the plaintext/ciphertext into the covertext.
The normal procedure is to first encrypt the plaintext to generate the ciphertext, and then modify the covertext in some way to contain the ciphertext. The generated stegotext is sent over to the intended recepient. If a third party snoops the stegotext in between, then they will just see some harmless looking picture (or sound, etc). Once the recepient receives the stegotext, the ciphertext is extracted from it by reversing the logic that was used to embed it in the first place. The ciphertext is decrypted using the traditional cryptography to get back the original plaintext.
◾️ You can download it HERE ◾️
Using OpenStego is pretty straightforward. There are two modes of operation - data hiding and watermarking.
1. Data Hiding:
- In this mode you can either hide the data (original.txt) inside an image or extract the data from the image. Check screenshots below to see how it can be done:
- This is my image that I want to use to hide text above (captcha.jpeg):
- Open the OpenStego and hide your data:
You can use AES128 or AES256 encryption - it's up to you.
2. Extract Data into OpenStego:
- After you've done the encryption or received an encrypted file from someone - and you have the password - perform the procedure below:
- After extracting the data and the password is correct, you will have the original.txt file, just open and see the contents:
You can use digital watermarks as well, but that will be shown later in another post. 👽💻