Comparative Analysis of tools used for Image Steganography

The word “Steganography” belongs to the Greek words Steganós and Graptoswhich stands for ‘covered writing’.Steganography is a historic technique of hiding messages within a carrier medium, more or less in plain sight. Digitally, the media used for this technique include audio files, images, text files, and videos. The carrier medium and message encoded within it together create a stego file that can be images, ciphertext, or plaintext.

Steganography involves hiding information in the electronic media that is used i.e., carriers, that results in changes in the media properties which may lead to some sort of deterioration, further hinting towards some form of tampering. For example, in images, these changes are visible and may be suggestive of investigating to determine the methods and tools used for this purpose. These changes can suggest the presence of a hidden message, thus nullifying the purpose of steganography.

In Image steganography, a message is hidden in the pixels of a picture. The message to be hidden is covered within a digital image using specialized concealing techniques. To conceal data, direct message insertion might encrypt either the complete information in the image or introduce the message in noisy areas, i.e., areas with natural color variation and tend to be ignored as unwanted. The message can even be randomly distributed throughout the image.

Steganography is widely used for concealing information and thus has a multitude of applications: -

• i. Steganography helps in transferring messages from one destination to another in a secretive manner.
• ii. Makes sure that no one tampers with the message that had been sent. A hash value of the message is produced of a pre-determined string length. This is then encoded and transmitted along with the message. Upon receiving the message, the receiver decodes it and compares both hash values. Any difference in hash values indicates tampering of some kind.
• iii. It can be used for the military.
• iv. It turns out to be very useful for the private banking sector.
• v. It can also be used for secure online voting.

Steganography is an age-old technique of hiding messages in any other medium of communication. Digitally, the media used can be audio, image, text, or video. It is used to transfer these messages from one destination to another in a secretive manner. Due to such an art, this is being exploited by various criminals including terrorist groups for easy transfer of messages, plagiarizing movies, stealing and transporting data from social media, and also producing pirated software. Thus the objective of this study is to compare commonly used free-to-use tools for image steganography like Digital Invisible Ink Tool Kit, Hide N Send, QuickStego, S Suite Picsel, Steganography X Plus, Xiao Steganography, OpenPuff, Image Steganography, SilentEye, and SteganPEG, to identify the most efficient tool based on certain parameters like Peak Signal to Noise Ratio (PSNR), Size, Structural Similarity Index Measure (SSIM), Size On Disk, Histogram, Color Variation, Visual Comparison, Metadata, User Interface, Accepted Input File Format, Accepted Output File Format, and Password Protected. After conducting the study and analyzing the results, it was determined that S Suite Picsel was the best performing tool for image steganography, followed by OpenPuff and Digital Invisible Ink Tool Kit (DIIT).

Vidyutma Badola

M.Sc. Forensic Science- Batch 2020-2022

bvidyutma@gmail.com

Supervisor- Shreya Arora