Secret Information Concealed Using Steganography ✓ Solved

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Steganography allows hiding sensitive information inside image (and audio) files. During a computer forensic investigation, you will need to analyze image files as part of the evidence. In addition to viewing the image looking for any illicit content, you should also consider analyzing all images files concealed data by means of steganography. For this exercise, each student will use steghide to embed a Word document within an image file, but keep a copy of the original file. Next, students post both the original image file and the modified image to the Week 8 – Assignment forum. Finally, each student will analyze both images from another student with any image viewer and with WinHex to determine the original file and the modified image.

In addition, use stegdetect with the modified file and comment on the outcome. Report the required steps for these tasks. Validation/Evaluation. What are some of the options for the steghide command? Do the original and modified images look the same? Can a hex editor help revealing the presence of hidden information? Can stegdetect recognize the presence of hidden information?

Steganography is a method of concealing information, where secret data is embedded within an unsuspecting file, usually an image or an audio file. In the context of computer forensic investigations, analyzing image files becomes crucial, considering the potential illicit content hidden within these digital assets. The focus of this assignment is to understand the use of the steghide tool to embed a Word document within an image file and subsequently analyze the differences between the original and modified files using various tools such as WinHex and StegDetect.

Understanding Steganography

Steganography is differentiated from encryption; while encryption scrambles the data to hide its contents, steganography utilizes inconspicuous methods to embed data within other files. This makes it an effective technique for concealing sensitive information without drawing attention. In this exercise, students will use Steghide, a well-known steganography tool that provides functionalities for embedding and extracting hidden information.

The embedding process will involve hiding a Word document named DocumentToHide.doc into an image file called Stega01.jpg. Steghide employs algorithms such as AES (Rijndael) for encryption purposes and allows adjustment of the compression level to optimize file sizes while ensuring the content remains undetectable to the human eye.

Step-by-Step Process

1. Download and Installation: The first step is to download Steghide from the EC-Council Certification Portal and unzip the files to a specified directory (C:\steghide). Following the installation, one needs to open the command prompt and navigate to the directory.

2. Prepare Files: The Word document (DocumentToHide.doc) and the image (Stega01.jpg) should be moved to the working directory. It's essential to ensure that the image file has sufficient capacity to hold the embedded document. This can be verified using the command steghide --info Stega01.jpg.

3. Embedding the Document: Once the file capacities are confirmed, the embedding process can be initiated using the command steghide --embed -ef DocumentToHide.doc -cf Stega01.jpg -p steganography -e rijndael-128 -z 9 -v. This command not only hides the Word document but also encrypts it for security.

4. Verification of Image Quality: After embedding, the modified image must be opened in an image viewer to confirm that it appears unchanged to the naked eye. Any discrepancies noticed between the two images during visual inspection can indicate successful embedding.

Analysis of Images

After embedding the document and confirming the modified image’s appearance, the next phase is peer interaction where students exchange their images. Utilizing WinHex, the original and modified images should be analyzed. This hex editor enables a deeper inspection of the file contents, identifying discrepancies in data structure, especially areas with unusual blocks of zeroes indicative of embedded file data.

Utilizing StegDetect, one can further assess the presence of hidden information. After analyzing Img01.jpg and Img02.jpg, it becomes evident that even though both files display identical images, their hexadecimal contents differ significantly. For instance, Img02.jpg may show Adobe Photoshop header information or unusual zero-value blocks, reinforcing the conclusion that modifications have occurred.

Final Observations

Steganography continues to pose challenges in digital forensic investigations because of its subtlety. As evidenced in the assignment, the ability to visually confirm that an image appears unchanged while containing hidden data shows the potency of steganographic techniques. A crucial takeaway from this analysis is the importance of utilizing a blend of tools: image viewers for visual checking, hex editors for content inspection, and automated tools like StegDetect that can simplify the discovery process.

Furthermore, understanding the capabilities of each tool and their respective outputs is critical for forensic analysts as they contend with digital evidence. The experience gained from employing steganographic analysis fosters critical thinking that can be applied to real-world scenarios. Knowledge of steganography's implications and proper handling of such evidence can equip professionals to navigate and uncover illicit activities effectively.

References

  • Johnson, N. F., & Jajodia, S. (1998). Exploring Steganography: Seeing the Unseen. IEEE Computer Society.

  • Wang, H., & Wang, S. (2004). Advanced Techniques for Data Hiding. Springer.

  • Fridrich, J. (1998). Image Steganography. IEEE Transactions on Information Forensics and Security.

  • Wayner, P. (2002). Disappearing Cryptography: Information Hiding: Steganography and Watermarking. Morgan Kaufmann Publishers.

  • Sharma, P., & Dutta, A. (2014). A Survey on Steganography Techniques in Digital Images. International Journal of Computer Applications.

  • Chandramouli, R., & Memon, N. (2001). An Overview of Image Steganography. Proceedings of the IEEE International Conference on Image Processing.

  • Zhang, Y., & Bhargav, J. (2010). Review of Steganographic Techniques in Digital Media. Journal of Digital Information Management.

  • Smith, T. J. (2002). Steganography and Steganalysis: An Overview of the Current State of the Art. ACM Computing Survey.

  • Khan, M., & Kaur, G. (2011). A Review of Digital Image Steganography Techniques. International Journal of Computer Applications.

  • Sutcu, Y., & Saga, M. (2008). Secure Image Steganography Using a New Robust Watermarking Technique. IEEE Transactions on Dependable and Secure Computing.

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