How does steganography hide messages

The software was developed to help whistleblowers and other activists retain their anonymity. Like just about everything else in our lives, steganography has made its way into the digital realm. Media files are some of the most popular places to hide information, because their large size means that more secret data can be stuffed inside them without raising suspicion. There are three separate ways that information can be hidden in files:.

Videos are relatively large files, so they can hide more data than most alternatives. Some of the most common techniques include a variety of different schemes for substituting the least significant bits polynomial equations, hash-based, etc. Alternatively, data can also be embedded into each frame, or filtering and masking data can be used as well.

There are a range of video steganography programs available online. One of the most interesting cases of video steganography was uncovered when the German authorities arrested a suspected al-Qaeda member in Officers searched the man and found a flash drive as well as memory cards in his underwear.

Among the other files was a pornographic video called Kick Ass. Because he was suspected of being involved in terrorism, the authorities investigated the video further to discover that steganographic techniques had been used to hide more than one hundred al-Qaeda documents.

These included terrorist training manuals and plots for future attacks. When the authorities find encrypted files, their suspicions are often raised , wondering why the file was encrypted in the first place.

The authorities would know something is up and be more likely to inspect the data further and discover the hidden information.

Because pornography is generally taboo, particularly for Muslims, the authorities might view the content, then just wave the person off as a sexual deviant filled with shame, rather than inspecting the data further. In a Russian spy ring was busted by US authorities. As part of their communications process, they would encrypt data, use steganography to hide it in pictures, then post them on public websites.

Steganography has also been used to steal intellectual property. In a GE engineer conspired with a business partner based in China to steal company secrets related to steam and gas turbines. At first, he just copied files to a flash drive. He was caught, and the company blocked USB ports and banned flash drives from being used.

He took data from 40 Matlab and Excel files, used steganography to hide it in a picture of a sunset, then emailed it to himself, before forwarding it on to his business partner. He was caught by GE, then charged with six counts of economic espionage. In a worrying trend, steganography is also becoming more common among hackers.

Researchers from Trend Micro analyzed the efforts of a Twitter account that posted malicious memes in October Once the malware was running on a device, it downloaded the memes from the Twitter account, then extracted a malicious command hidden inside them. It took a screenshot of the infected computer, and sent the information back to the attacker after it collected the control server details from Pastebin.

Audio steganography also comes with a range of different methods. Some of the most common techniques include:. A Polish researcher used audio steganography in an interesting project. He took the song Rhythm is a Dancer by Snap! When a beat was slowed down, it represented a dash in Morse code, and when a beat was sped up, it signified a dot.

He then played the song to a mix of professional musicians and laymen. With a one percent tempo discrepancy, no one noticed that anything was amiss. It was only at around two percent that the professional musicians knew that something was up, and around three percent for everyone else.

When it comes to text, there are many different ways to hide information. One simple technique involves opening Microsoft Word, typing out your secret message, then changing the text color to white.

You can then save it and send it to your co-conspirator, making sure that you instruct them over a secure channel on how to access the information. Otherwise, they might be perplexed at why you keep sending them blank documents.

All they have to do is select the text and your plot is foiled. Because we are so used to ignoring spam, a message like this could easily fly under the radar and allow you to communicate without being detected.

The usefulness of the software is debatable, but at the very least, it shows that messages can be hidden in a wide range of ways — you just have to think outside the box. The internet is incomprehensibly large, containing a wealth of strange and nonsensical information. This leaves a lot of opportunities to hide secret messages in public without raising any suspicions. Just think of all of the absurd comments you have come across on forums or social media, and the thousands of blog posts that made absolutely no sense.

We tend to either brush them off or read them for our own amusement, but never consider that there could be something more to them than lunacy. The Intercept claims that even the NSA has been in on the practice, using its official Twitter account to communicate with Russian spies. In a clandestine operation, the Intercept reports that some of the participants leaked the details of NSA Tweets to Russian operatives before they were posted.

According to the report, this acted as confirmation that they were in fact representatives of the NSA, and not just scammers. Steganography can be incredibly difficult to detect, especially when there is no reason to be suspicious. This is what makes it so hard to talk about good steganography. Techniques are actively being researched and the technology is improving, but its very nature makes it impossible to detect successful steganography in the wild.

There may also be a variety of techniques developed outside of the public sphere, by intelligence agencies, terrorist networks and criminals gangs. Despite this, a lot of analytical tools we can be applied when we suspect that steganography is being used to hide messages. However, the right tool depends on which techniques concealed the data in the first place.

When it comes to invisible ink, the detection methods depend on what kind of invisible ink was used. If it has been done poorly, there may be scratch marks on the paper, a change in its texture, or a differing reflection where the writing has been hidden.

If a message is suspected to contain invisible ink, you can first inspect it visually and smell it for any irregularities. The next step is to pass it under an ultraviolet light, which shows several types of invisible ink. The message can then be exposed to heat, which may reveal other kinds of ink. Your adversary may be using a sophisticated invisible ink solution that you are unaware of.

Null ciphers can often be detected by anomalies in the text. They sometimes use strange turns of phrase as the creator tries to mold their secret message into the cover text. However, if the null cipher is done well and you have no reason to scrutinize it heavily, it can be simple for people to slip hidden messages past you. In suspicious text, interceptors should examine the fonts, spacing, sizing and many other factors.

The tiny size of microdots makes them almost impossible to detect, unless the interceptor is already wary. One method involves taking a high quality scan of the page, then zooming in on some of the white space. A bit color scheme, as the term suggests, uses 24 bits per pixel and provides a much better set of colors. In this case, each pix is represented by three bytes, each byte representing the intensity of the three primary colors red, green, and blue RGB , respectively.

The Hypertext Markup Language HTML format for indicating colors in a Web page often uses a bit format employing six hexadecimal digits, each pair representing the amount of red, blue, and green, respectively. The size of an image file, then, is directly related to the number of pixels and the granularity of the color definition.

Not all are equally suited to steganography, however. GIF and 8-bit BMP files employ what is known as lossless compression, a scheme that allows the software to exactly reconstruct the original image. JPEG, on the other hand, uses lossy compression, which means that the expanded image is very nearly the same as the original but not an exact duplicate. While both methods allow computers to save storage space, lossless compression is much better suited to applications where the integrity of the original information must be maintained, such as steganography.

The simplest approach to hiding data within an image file is called least significant bit LSB insertion. If we are using bit color, the amount of change will be minimal and indiscernible to the human eye. As an example, suppose that we have three adjacent pixels nine bytes with the following RGB encoding:. Now suppose we want to "hide" the following 9 bits of data the hidden data is usually compressed prior to being hidden : If we overlay these 9 bits over the LSB of the 9 bytes above, we get the following where bits in bold have been changed :.

This description is meant only as a high-level overview. Similar methods can be applied to 8-bit color but the changes, as the reader might imagine, are more dramatic. Gray-scale images, too, are very useful for steganographic purposes. One potential problem with any of these methods is that they can be found by an adversary who is looking.

In addition, there are other methods besides LSB insertion with which to insert hidden information. Without going into any detail, it is worth mentioning steganalysis , the art of detecting and breaking steganography. One form of this analysis is to examine the color palette of a graphical image. In most images, there will be a unique binary encoding of each individual color.

If the image contains hidden data, however, many colors in the palette will have duplicate binary encodings since, for all practical purposes, we can't count the LSB. If the analysis of the color palette of a given file yields many duplicates, we might safely conclude that the file has hidden information. But what files would you analyze? Suppose I decide to post a hidden message by hiding it in an image file that I post at an auction site on the Internet.

The item I am auctioning is real so a lot of people may access the site and download the file; only a few people know that the image has special information that only they can read. And we haven't even discussed hidden data inside audio files! Here are the latest Insider stories. More Insider Sign Out. Sign In Register. Sign Out Sign In Register. Latest Insider. Check out the latest Insider stories here. More from the IDG Network.

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