STEGANOGRAPHY:
A steganography is a technique involves hiding sensitive information within an ordinary, non-secret file or message, so that it will not be detected. The sensitive information will then be extracted from the ordinary file or message at its destination, thus avoiding detection. Steganography is an additional step that can be used in conjunction with encryption in order to conceal or protect data.
Steganography is a means of concealing secret information within (or even on top of) an otherwise mundane, non-secret document or other media to avoid detection. It comes from the Greek words steganos, which means “covered” or “hidden,” and graph, which means “to write.” Hence, “hidden writing.”
You can use steganography to hide text, video, images, or even audio data. It’s a helpful bit of knowledge, limited only by the type of medium and the author’s imagination.Steganography is a method that makes it easy to conceal a message within another to keep it secret. The result is that the hidden message remains hidden. A steganography approach can benefit images, videos, and audio files.
Different Types of Steganography:
1. Text Steganography − There is steganography in text files, which entails secretly storing information. In this method, the hidden data is encoded into the letter of each word.
2. Image Steganography − The second type of steganography is image steganography, which entails concealing data by using an image of a different object as a cover. Pixel intensities are the key to data concealment in image steganography.
Since the computer description of an image contains multiple bits, images are frequently used as a cover source in digital steganography.
The various terms used to describe image steganography include:
• Cover-Image - Unique picture that can conceal data.
• Message - Real data that you can mask within pictures. The message may be in the form of standard text or an image.
• Stego-Image − A stego image is an image with a hidden message.
• Stego-Key - Messages can be embedded in cover images and stego-images with the help of a key, or the messages can be derived from the photos themselves.
3. Audio Steganography − It is the science of hiding data in sound. Used digitally, it protects against unauthorized reproduction. Watermarking is a technique that encrypts one piece of data (the message) within another (the "carrier"). Its typical uses involve media playback, primarily audio clips.
4. Video Steganography − Video steganography is a method of secretly embedding data or other files within a video file on a computer. Video (a collection of still images) can function as the "carrier" in this scheme. Discrete cosine transform (DCT) is commonly used to insert values that can be used to hide the data in each image in the video, which is undetectable to the naked eye. Video steganography typically employs the following file formats: H.264, MP4, MPEG, and AVI.
5. Network or Protocol Steganography − It involves concealing data by using a network protocol like TCP, UDP, ICMP, IP, etc., as a cover object. Steganography can be used in the case of covert channels, which occur in the OSI layer network model.
Some of the Steganography Examples Include
• Writing with invisible ink
• Embedding text in a picture (like an artist hiding their initials in a painting they’ve done)
• Backward masking a message in an audio file (remember those stories of evil messages recorded backward on rock and roll records?)
• Concealing information in either metadata or within a file header
• Hiding an image in a video, viewable only if the video is played at a particular frame rate
• Embedding a secret message in either the green, blue, or red channels of an RRB image.
How attacker can attack through stegnography....
• Secure Cover Selection
Secure Cover Selection involves finding the correct block image to carry malware. Then, hackers compare their chosen image medium with the malware blocks. If an image block matches the malware, the hackers fit it into the carrier image, creating an identical image infected with the malware. This image subsequently passes quickly through threat detection methods.
• Least Significant Bit
That phrase almost sounds like a put-down, doesn’t it? However, in this case, it refers to pixels. Grayscale image pixels are broken into eight bits, and the last bit, the eighth one, is called the Least Significant Bit. Hackers use this bit to embed malicious code because the overall pixel value will be reduced by only one, and the human eye can’t detect the difference in the image. So, no one is even aware that anything is amiss, and that the image is carrying something dangerous within.
• Palette-Based Technique
Like the Least Significant Bit technique, the Palette-Based Technique also relies on images. Hackers embed their message in palette-based images such as GIF files, making it difficult for cybersecurity threat hunters or ethical hackers to detect the attack.
Steganography Tools
Various tools or software that support steganography are now readily accessible. Though most hide information, some provide additional security by encrypting it beforehand. You can find the following free steganography resources online:
• Steghide
• Stegosuite
• OpenPuff
• Xiao Steganography
• SSuite Picsel
ADVANTAGES OF STEGANAGRAPHY:
Steganography is a method that makes it easy to conceal a message within another to keep it secret. The result is that the hidden message remains hidden. A steganography approach can benefit images, videos, and audio files. Further advantages include:
• Unlike other methods, steganography has the added benefit of hiding communications so well that they receive no attention. However, in countries where encryption is illegal, sending an encrypted message that you can easily decipher will raise suspicion and may be risky.
• Steganography is a form of encryption that protects the information within a message and the connections between sender and receiver.
• The three essential elements of steganography—security, capacity, and robustness—make it worthwhile to covert information transfer via text files and develop covert communication channels.
• You can store an encrypted copy of a file containing sensitive information on the server without fear of unauthorized parties gaining access to the data.
• Government and law enforcement agencies can communicate secretly with the help of steganography corporations.
LIMITATIONS OF STEGNOGRAPHY:
One of the main limitations is that the amount of data that can be hidden within an image or other medium is limited by the size of the medium. Additionally, some steganography techniques can be detected by more advanced security measures, which can compromise the secrecy of the hidden data. Furthermore, some steganography techniques can be vulnerable to attacks by skilled adversaries who can detect and extract hidden data. Finally, it is important to note that steganography can be used for both legitimate and illegitimate purposes, so it is important to use it responsibly and within the bounds of the law.
There are many kinds of dedicated software applications available to facilitate steganography. Here is a partial list of the more well-known steganography applications:
• Image Steganography
• OpenStego
• Xiao Steganography
• Crypture
• NoClue
• Steganography Master
• Steghide
STEGANALYSIS :
Steganagraphy is a strong technique to hide a secure message, however, it also vulnerable when the technique used to spread malicious and harmful content by embedding. To identify such content, staganalysis has been performed. The counter technique of image steganography is known as image steganalysis, which begins by recognizing the object that exists in the embedded source file. The aim of this process is not to advocate the removal or disabling of valid hidden information such as copyrights, but to point out approaches that are vulnerable and may be exploited to investigate illegal and dishonest hidden information. Security threats analysis on hidden information may take several forms like detecting, extracting, and disabling or destroying hidden information. An attacker may also embed contradict information over the existing hidden data.
Applications of Steganalysis:
a. Medical safety: Current image formats such as Digital Imaging and Communications in Medicine separate image data from the text like such as patients name, date and physician details along with the result that the link between image and patient occasionally gets mangled by protocol converters. Thus embedding the patient's name in the image could be a useful safety measure.
b. Terrorism: According to government officials terrorists use to hide maps and photographs of terrorist targets and giving instructions for terrorist targets.
c. Hacking: The hacker hides a monitoring too, server behind any image or audio or text file and shares it with mail or chat which will get installed and executed which will help the hacker to do anything with the workstation.
D. Steganalysis Methods Steganalysis is the method, which detects the presence of hidden data; this process can be categorized by different types such as Statistical steganalysis which contains spatial domain. Transform domain and Feature based steganalysis. The Statistical steganalysis helps to detect the existence of the hidden message, statistical analysis is done with the pixels and it is further classified as spatial domain steganalysis and transforms domain steganalysis. In spatial domain, the pair of pixels is considered and the difference between them is calculated.
E. Classification of steganalysis:
There are certain types of algorithms available in the literature to perform classification; the classification is a supervised process where it needs a prior training to classify the data into normal or stego data. The steganalysis algorithm may or may not depend on the steganographic algorithm (SA). Based on this, steganalysis is classified as Specific and generic algorithms. Few algorithms depend on the steganographic algorithms and few not.
1. Specific steganalysis:
The SA is known and the designing of detector (steganalysis algorithm) is based on SA. The steganalysis algorithm is dependent on the SA. This type of steganalysis is based on analyzing the statistical properties of an image that change after embedding. The advantage of using specific steganalysis is the results are very accurate. The specific or target steganalysis are very limited to particular embedding algorithm. So it is not fully applicable for all types of algorithms. And it also not supports all image formats.
2. Blind / Universal steganalysis:
In universal method, the steganalysis algorithm is not recognized by all. Therefore, anyone can design a detector to detect the presence of the secret message that will not depend on steganalysis algorithms. Comparing with specific steganalysis, universal is common and less efficient. Still universal steganalysis is widely used than specific one because it is independent of the SA.
Steganalysis tools Steganalysis usually consist several processes like cropping, blurring, image resizing, noise removal and compression process. Various steganalysis tools are available to detect the presence of hidden information with the stego image. And few tools only provide the above process.
Some of the steganalysis tools are mentioned below:
1. StegDetect.
2. StegSecret.
3. JPSeek.
4. StegBreak
5.StegSpy
6.Stego Suite
Digital steganography refers to modifying a digital object (cover) to encode and conceal a sequence of bits (message) to facilitate covert communication. Digital steganalysis refers to efforts to detect (and possibly prevent) such communication.
LIMITATIONS OF STEGANOLYSIS:
One limitation is that existing steganalysis models lack dynamic extensibility for new steganographic algorithms, which limits their application in real-world scenarios. Another limitation is that steganalysis methods based on user behavior during chat, such as timing steganography detection, are not very robust.
Conclusion:
Steganography is a clever and fascinating technique for sending confidential information in plain sight. Digital steganography can be used for benevolent and malicious purposes, making it crucial that cybersecurity experts thoroughly understand this practice. The steganalysis plays an important role in the current trend. Detection and analysis of steganographic images are the most important process in several real-time applications. The lack of training samples for steganalysis make these processes much complicated. This steganalysis process can be performed by effective classification and image processing techniques and approaches. In this article, we reviewed several different methods to achieve effective steganalysis on different steganographic techniques.
