How does steganography conceal data

It is the first program in offensive technologies in India and allows learners to practice in a real-time simulated ecosystem, that will give you an edge in this competitive world. Ajay Ohri 9 Dec Introduction Can you imagine if you had the ability and power to conceal and hide information within plain sight?

What is Steganography? How does it Work? Types There are different ways to hide a message. The most common are: A Steganography in Images Digital images are used widely and since they are available in various formats the algorithm used differs completely. Some common kinds are: Least significant bit insertion. Masking and filtering. Redundant Pattern Encoding.

Encrypt and Scatter. Algorithms and transformations. Least significant bit insertion. B Steganography in Audio Implanting a secret message in audio is most difficult as the human brain has a wide range of auditory capacity. A few methods used are: LSB coding. Parity coding. Phase coding. Spread spectrum. Echo hiding.

C Steganography in Video In this, a video file will be embedded with supplementary data that will hide the secret message. Some widely known approaches are Least Significant Bit Insertion. Real-time Video Steganography. D Steganography in Documents This involves focusing on altering the characteristics of documents. A few ways this is done are: Hiding information in plain text by adding white space and tabs to the end of the lines of documents.

Using a widely available cover source like a book or newspaper and using a code comprising of a combination of numbers, letters, or line number. This revealed the secret message I wanted to share. Ever do that yourself? Well, if you have, you and I have engaged in the time-honored practice of steganography. Steganography is the practice of hiding a secret message inside of or even on top of something that is not secret.

That something can be just about anything you want. These days, many examples of steganography involve embedding a secret piece of text inside of a picture.

Or hiding a secret message or script inside of a Word or Excel document. The purpose of steganography is to conceal and deceive. It is a form of covert communication and can involve the use of any medium to hide messages. Instead, it is a form of data hiding and can be executed in clever ways. Steganography is a technique that can hide code in plain sight, such as within an image file. When they open a picture on a device, few people ever have reason to look beyond the visual presentation displayed to what lies hidden inside the.

Steganography is a form of obfuscation that is quite different from cryptography, which is the practice of writing coded or encrypted messages. Cryptographic messages are obviously hiding something: they typically look like gibberish and require specialist methods to decode.

Steganographic messages, on the other hand, look like ordinary messages but artfully conceal something unexpected. A simple example using a familiar technique illustrates the basic idea behind steganography:. In this trivial example, it is the human brain that decodes the concealed message in the plain text, but computer programs read bytes, not natural language, and this turns out to make it possible to conceal messages in plain sight that are easy for computers to parse and simultaneously almost impossible for humans to detect without assistance.

Depending on the technique used, this can also be done without inflating the overall file size of the original image. One simple method is simply to append a string to the end of the file. The output from hexdump shows us the extra bytes added. The plain text string can easily be dumped out or read by a program.

The authorities may monitor everything going in and out of your cell, so you would probably have to hide any communication that takes place. In this kind of situation, steganography would be a good choice. It may be challenging with the resources you have at hand, but you could write a plain sounding letter with a hidden message concealed with different font types or other steganographic techniques.

However, since the content of the conversation is top secret, the diplomat may want to use cryptography and talk over an encrypted line. If spies or attackers try to intercept the conversation, they will only have access to the ciphertext, and not what the two parties are actually saying.

If the political activist used cryptography to communicate with their organization, the authorities would most likely have intercepted it. The officials would see the ciphertext and know that the activist was trying to send encoded messages, then they would most likely stop its delivery and interrogate the activist about it.

Conversely, diplomats are often monitored by their host countries. If a diplomat tried to send steganographically concealed messages back home, they could be intercepted, analyzed and the content may be uncovered. If you wanted to hide the fact that communication was taking place, but also protect the message in case it was discovered, you could first encrypt it and then conceal it with steganography.

Using the cipher, you could shift each character to the one that follows it in the alphabet, giving you a ciphertext of:. Now that you have your cipher text, you can write it down on your piece of paper with lemon juice or whatever kind of invisible ink you have at hand. As long as your recipient knows where the message will be, how to reveal it heat, in this case and how to decrypt it, they will be able to access the secret communication. If you wanted to increase the security of the communications, you could use more sophisticated encryption and steganography methods, such as AES and bit plane complexity segmentation BPCS , respectively.

Steganography has a number of surprising applications, aside from the obvious one of hiding data and messages. Hackers use it to conceal code in malware attacks. Printers use steganography as well, hiding imperceptible yellow dots that identify which printer created a document and at what time.

Steganographic techniques are also frequently used in watermarking and fingerprinting to prove ownership and copyright. Steganography is a useful practice, but it does have a number of limitations. There are two key factors that are often in competition — the first is how obvious and easy the hidden data is to detect whether by human perception or other forms of analysis , while the second is how much data can be hidden in a given file or piece of communication.

The higher the percentage of data someone tries to conceal, the easier it is to spot. How much data you can safely include in a given file will depend on the steganographic technique, risk level, and amount of scrutiny expected.

At lower percentages, the image will look essentially the same. As more data is packed in, the quality starts to deteriorate and you may even be able to see elements of the hidden picture. With this technique at a low risk level, you would want a five gigabyte file for each gigabyte that you want to hide. This makes steganography relatively inefficient. If your goal is to keep data secure and confidential, rather than to obscure the fact that communication is taking place, cryptography is generally a better option.

On top of the efficiency problem, the recipient also needs to know where and how information has been hidden so that they can access it. This generally means that you will need access to a secure channel so that you can discuss these details without any attackers intercepting them. Because secure channels are often difficult to come by, particularly in situations that require steganography in the first place, this can be a difficult problem to surmount. It depends on the situation, but if keeping information secure and inaccessible to unauthorized parties is of the utmost importance, then data should be encrypted with a private key before steganographic techniques are applied.

There are too many types of steganography to cover each one, so we will stick to the more commonly used and interesting forms, giving examples of how they are used.

Steganography was developed well before computers, so there are a range of non-digital techniques that we can use to hide information. Throughout history, invisible ink has been one of the most common steganographic practices.

It works under the principle that a message can be written without leaving any visible marks, only to be revealed later after a certain treatment is applied. A wide range of substances can be used as invisible inks. Some of these include lemon juice, cola, wine, vinegar, milk, and soapy water, all of which can be made visible by heat.

Laundry detergents, sunscreen, soap and saliva are also invisible inks, but they are revealed by ultraviolet light instead.

There are also a number of combinations where the first ingredient is used to write and the second causes a chemical reaction that makes the image visible. These include starch and iodine, iron sulfate and sodium carbonate, vinegar and red cabbage water, phenolphthalein and ammonia fumes, as well as salt and silver nitrate.

Likewise, if the writing process leaves behind any signs, such as a different texture, scratch marks or an altered sheen, the invisible ink might be detected by the enemy. He created a spy group in , and messages would frequently be sent between the members. They would often write a legitimate shopping list with an invisible ink message hidden underneath, just in case the note was intercepted. They used an ink developed by Dr.

James Jay. The letters were also frequently written in code, just in case the British came across one of the messages. Combining steganography with encryption added another layer of protection.

Null ciphers hide their real messages amid seemingly normal text, using a range of different techniques. Common examples include creating a mundane text, where every nth word, or even letter, is part of the secret message. For example, if we use a null cipher where every fifth word is our real message, we can take a message like:.

You can create and use null ciphers according to just about any scheme you can think of, as long as your recipient knows the technique.