Understanding Steganography: Tools & Software

Introduction

Steganography is the practice of hiding information in other data to conceal the existence of the hidden message. This technique has been used throughout history to transmit secret information covertly and has been adapted for use in the digital age. In digital steganography, the hidden message is embedded in an image, audio file, or other digital media in a way that is not easily noticeable. The hidden message can be recovered by extracting the information from the cover media, typically using specialized software or tools.

Steganography is often used in security and privacy protection to conceal sensitive information from prying eyes. For example, a person may want to hide a confidential message in an image file and send the image file over the internet with the hope that the message will be secret.

Learning Objectives

1. To Understand the basics of steganography
2. To Get familiar with steganography tools and software
3. To Understand the role of steganography in security and privacy
4. To develop the skills to apply steganography in real-world scenarios
5. To understand the limitations and risks of steganography

This article was published as a part of the Data Science Blogathon.

Table of Contents

1. Understanding the History
2. Why Should we Use Steganography?
3. A Peek into the Problem Statement
4. Function of Steganography
5. System Requirement for Steganography
6. Implementation of Steganography in Python
7. What’s the Difference Between Steganography and Cryptography
8. Benefits of Steganography
9. Conclusion

Understanding the History

Steganography has a long history, dating back to ancient civilizations. The word “steganography” comes from the Greek words “steganos,” meaning “covered or concealed,” and “graphie,” meaning “writing.”

One of the earliest known examples is from the ancient Greeks, who would shave the head of a messenger, tattoo a message on their scalp, and then let their hair grow back before sending them on their way. The message would be revealed only when the messenger’s hair was shaved again at their destination.

In the modern era, steganography has mainly been used for digital communication or message transmission, as computers have made it possible to conceal messages in digital files, such as images, audio, and video files, in a way that is difficult to detect.

Why Should we Use Steganography?

Steganography is the practice of hiding information in other, seemingly harmless information. It is often used to conceal sensitive information, such as messages or files, in other media types, such as images or audio files. The goal is to conceal hidden information, making it difficult for an eavesdropper or other unauthorized person to detect it. This makes steganography useful for protecting information from unauthorized access or tampering.

A Peek into the Problem Statement

A problem statement in steganography refers to the specific challenge or requirement the steganographer is trying to solve. Some common problem statements include:

• Concealing the Existence of a Message: This is the basic problem statement in steganography, where the task is to hide a message in another piece of information (e.g., an image, audio file, etc.) without leaving any visible signs that the message is there.
• Concealing the Existence of a Message From Specific Individuals or Groups: This problem statement involves hiding a message so that it can only be deciphered by specific individuals or groups who possess the necessary key or knowledge to decrypt it.
• Concealing the Existence of a Message and Providing a Level of Security: This problem statement involves hiding a message so that it can only be read by authorized parties and providing a level of security to protect the message from being read by unauthorized parties.
• Hiding Multiple Messages in a Single File: This problem statement requires the steganographer to hide multiple messages in a single file so they can all be retrieved later.
• Hiding a Message Such That it can be Retrieved in Multiple Ways: This problem statement involves hiding a message so that it can be retrieved using multiple methods, making it more difficult for unauthorized parties to detect.
• Hiding a Message in a way that it can be Retrieved in a Specific Sequence: This problem statement involves hiding a message so that it can only be retrieved in a specific sequence, providing an additional level of security.

Function of Steganography

The main function of steganography is to conceal the existence of a message or information in another message, image, or file. This can be achieved by using various techniques such as:

1. Linguistic Steganography: Hiding a message in a text or speech using subtle language changes, such as spelling or grammar variations.
2. Digital Steganography: Hiding a message in a digital image, audio, or video file by manipulating bits and bytes of the file. This can be done using the least significant bit insertion, masking, and filtering techniques.
3. Physical Steganography: Hiding a message in an object or physical space using techniques such as microdots, invisible ink, or special symbols.

The goal is to make the hidden message or information undetectable so that it can only be accessed by the intended recipient, who has the knowledge of the method used to conceal the message.

System Requirement for Steganography

A software program and hardware device capable of running a python project. For example, we need a python runtime environment on the System.

Implementation of Steganography in Python

Module installation-

You can use the python package installer pip to install the OpenCV-python module. We can install it by running the following command in the terminal or command prompt:

pip install opencv-python

If you already have OpenCV-python installed and you are still getting an import error, make sure that the OpenCV-python module is properly installed and its path is included in the environment variable PYTHONPATH; you can check this by running the following command in your terminal:

pip list

Python Code-

Here is the sample code to encrypt the information-

import pyfiglet
ascii_banner = pyfiglet.figlet_format("STEGNOGRAPHER- ENCRYPTER")
print(ascii_banner)
import cv2
loc=input("Enter the path of image (with extension) -> ")
image=cv2.imread(loc)
txt=input("Enter the data that you want to Encrypt (add '$' at the END of your statement) :- ")
ls=(list(txt))
for i in range(0,len(ls)):
     data=ord(ls[i])
     image[0,i,0]=data
lc=input("Enter saving location (Extension should be .png) ->")
cv2.imwrite(lc,image)
print("Data Encrypted")
input("")

Encrypting the data in the image.

Here is the sample code to decrypt the data-

import pyfiglet
ascii_banner = pyfiglet.figlet_format("STEGNOGRAPHER- DECRYPT")
print(ascii_banner)
import cv2
d=[]
loc=input("Enter the path of image (with extension) -> ")
image=cv2.imread(loc)
x,y,z=image.shape
for i in range(0,y):
     b=chr(image[0,i,0])
     #print (b)
     if(b=='$'):
          break
     else:
          d.append(b)
d=''.join(d)
print(d)
input()
print("You can close the window now.")

NOTE: Here, I’m using pyfiglet module to create a banner to look good. You can remove stating 3 lines if you do not want it.

What’s the Difference Between Steganography and Cryptography?

Steganography and cryptography are both methods of hiding information, but they do so in different ways.

Steganography hides information in other information, such as a message in an image. The goal is to conceal confidential information rather than protect it from being read by an unauthorized person.

Cryptography, on the other hand, protects information by transforming it into a code or cipher. Cryptography aims to make the encoded information unreadable to anyone without the key or means to decrypt it.

In short, steganography is the art of hiding information in plain sight, while cryptography is the art of securely encrypting information.

Benefits of Steganography

• Concealment: One of the benefits of steganography is that it allows for the concealment of information, making it difficult for third parties to detect the existence of a message or file.
• Security: By hiding information in another file or message, steganography can provide an additional layer of security, protecting data from unauthorized access.
• Evasion Of Detection: It can be used to evade detection by firewalls, intrusion detection systems, and other security measures.
• Resistance to Tampering: Because the hidden information is embedded in another file or message, it is less likely to be tampered with, making it more secure.
• Digital Watermarking: It can be used to embed digital watermarks, which can be used to identify the source of a file or detect unauthorized copies.
• Anonymity: By hiding the existence of a message or file, it can also provide anonymity for the sender and recipient.
• Cover Text: It can be used to conceal sensitive information in a cover text.
• Compression: It can also be used to improve data compression.

It should be noted that Steganography is not foolproof and can be detected by specialized software or through statistical analysis.

Conclusion

Steganography is a powerful and versatile technique for hiding information in other data. The technique has a long history and has been adapted for use in the digital age to meet the demands of modern security and privacy needs.

Steganography provides a way to transmit confidential information securely and covetable manner and is often used as an alternative or complement to cryptography. By embedding secret messages in cover media, steganography allows individuals and organizations to protect sensitive information from prying eyes and ensure the confidentiality of their communications.

The key takeaways from this article are:

• Steganography is a technique for concealing information by embedding it in other data.
• Its purpose is to keep the existence of the hidden message a secret rather than making it unreadable.
• Steganography has been used throughout history and has become popular in the digital age for protecting sensitive information.
• It can be used as an alternative or complement to cryptography.

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Abhishek

Software Engineer || Co- Founder || B-Plan contest finalist at IIT Kharagpur || 1st Rank on SQL- Hacker Rank

Having 2 years of experience in the IT industry and publish two research papers (A Data Visualization Tool- Grafana, Blue Brain Technology).