Steganography is a technology that hides secret messages in digital files, and while it can be useful for information security, it also has the potential to be used for criminal purposes and should be used with caution.
In recent years, the internet has become increasingly integral to modern life. We use it all day long to see the world, send messages to each other, and communicate with the rest of the world. In the flood of information, people are constantly exposed to a variety of content, and the distance between people has become closer psychologically even if they are physically far away. With this increased interaction in the online space, the importance of privacy and data security is also increasing. In particular, the secure exchange of secret digital information is becoming a major challenge in modern society. Steganography is gaining attention as one of the solutions.
Steganography, which is a combination of the words “stegano,” meaning “hidden,” and “graphos,” meaning “to communicate, write,” is a deep cryptographic technology that encrypts and hides the information you want to convey in seemingly ordinary image files, audio or video files, etc. The main purpose of the technique is to hide a secret message within a plain message so that others don’t know it exists, and it is often used to communicate confidential information.
The first documented use of steganography was in the 5th century BC. Histaeus, a Greek king held hostage by King Darius, wanted to deliver a secret message to his adopted son in Miletus, so he shaved the head of a slave and tattooed the message on his head. When the slave’s hair grew out and the tattoo became invisible, the king sent the slave to his adopted son. This example from ancient Greece shows how strong the human instinct to keep secrets was even then. Here are some other examples of how steganography has been used in the past The ancient Romans wrote letters using invisible ink made from natural sources such as fruit juice and milk, which could only be read by holding it up to a light. Also, during World War II, the Germans invented “microdots,” a technology that shrinks secret messages to the size of a dot. The shrunken secret message could be disguised as a dot embedded in the writing, such as the dot in the letter i, allowing large amounts of data to be sent surreptitiously. The idea of steganography – hiding the existence of a secret message – has been around since ancient times. It wasn’t until around 1985, after the invention of computers and the internet, that the technique was applied to digital information and files.
Steganography differs from common cryptographic techniques, which hide the message itself, by hiding it in another medium to conceal its presence. Steganographic techniques use two main methods to hide messages: embedding and modification. An embedding technique appends additional data to the front or back of a file without changing the data in the file, leaving the original file unaffected. Modification techniques modify the least significant bits (LSBs) of RGB values in an image file. In other words, the pixels that make up an image file have RGB values, and by subtly changing the numbers of those RGB values, information is hidden. Modification techniques affect the original file in a different way than insertion techniques, but they are popular because the modification of the least significant bits is not noticeable to the naked eye. These techniques have become highly sophisticated and are essential tools for information security in the digital age.
Steganography can be used in a variety of ways, not just to hide state secrets. For example, steganography is used to protect the copyright of content by hiding creator or copyright information in multimedia data. Especially in the modern digital age, copyright infringement has become an increasingly serious problem as countless creative works are shared over the internet. If a third party who does not know whether steganography has been enabled or not has arbitrarily converted the original data, the copyright-related data hidden inside can be extracted and examined to determine whether it is the original or an arbitrarily converted copy. As the number of creative works on the Internet increases and intellectual property rights for content expand, steganography is expected to be used more actively.
However, steganography can also be used for criminal purposes. Steganography is often used by terrorist organizations to issue terrorist orders and exchange information. It is known to have been used by international terrorist leader Osama bin Laden to send and receive messages to and from his terrorist organization during the September 11, 2001 attacks. Bin Laden hid airplane drawings in photos of the Mona Lisa and emailed them to terrorist organizations. Steganography can also be used to spread malicious code. It turns out that steganography has long been used to hide malware, not just as a simple encryption technique to secretly deliver messages. When a user clicks on an image, audio, or video file that contains malware, the malware installs itself on the user’s PC and initiates further criminal activity. This criminal use case illustrates the dangers of steganography. Attacks that utilize steganography are nearly impossible to identify with the naked eye and are very difficult to detect with existing malware detection tools or defense software, so the only way to prevent these criminal activities is to update your software regularly. As you can see, steganography can be used for good, such as communicating classified state secrets or protecting the copyright of creative works, but it can also be used for criminal purposes.
As you can see, steganography has a wide range of applications. However, the following disadvantages should not be ignored if the technology is to become more widely used. The disadvantage of steganography is that it involves embedding a secret file inside an ordinary file, which can raise suspicions because the file size is larger than the apparent message. To avoid this, you should be more careful with the size and format of the file and, if necessary, use additional encryption techniques. The steganographic modification techniques used in the image files mentioned above are difficult to detect with the naked eye, but can be detected by comparing pixel values. Another weakness of steganography is that the files it hides are only hidden by their existence, and most of them are not encrypted, so if it is discovered that they are steganographic, the tool can be used to reveal the secret message.
So far, we’ve learned about a technique called steganography. Steganography is a technique for hiding secret messages in plain image or video files. Steganography is invisible to the naked eye, so it’s hard to tell that the message is even there. This characteristic makes the technology versatile, especially in the digital age. However, in order for this technology to be applied in more fields, its shortcomings will need to be further improved. Therefore, if we can overcome the weaknesses of steganography and avoid exploiting it, we can improve the technology and make it more widely used in a positive way.
