Modern man has thousands of ways to transmit information in the blink of an eye to anywhere in the world. We endlessly broadcast videos, send emails and exchange various files.
True, you have to pay for comfort. Never before have people’s personal data been as vulnerable as it is today. When sending a message or forwarding a file, you cannot be sure that someone else will not look into it. But at least you can try to minimize the risk.
One good way to do this is to hide valuable information where no one would think to look. For example, inside a picture or a musical composition.
Encryption or masking?
When it comes to security, many experts recommend simply encrypting files or transferring them over secure channels. For example, many modern messengers have an end-to-end encryption function. The transmitted data in this case is available only to the sender and recipient. No third parties have access to the information.
Alas, with all the reliability of such encryption, the method has no “foolproof” protection. If attackers intercept the transmitted information, they will not be able to decrypt it. But if they can hack directly into the sender or recipient, they will see everything in full view.
In this sense, “masking” information seems to be a more reliable method. Even if you are hacked, it is unlikely that the hacker will guess that the cat picture you sent contained a hidden message.
How it works?
In short, part of one file is embedded inside another. This does not change the basic structure of the second file, so it can still be used as intended. If you embed something in an image, that image can be opened in an editor or viewer. If you embed something in a music track, that track can be listened to. The only thing that will change is the size of the container file. It will become larger by the size of the attachment file. Keep this in mind when creating a disguise. A small picture weighing several tens of megabytes looks suspicious.
If you intend to use this method to communicate with another user, the recipient must be warned in advance that you will be sending him messages in disguise. Moreover, this should be reported through another information channel. Best of all – in person. If you send a picture with a hidden message by e-mail, and in the same letter reveal the secret of the attachment, the whole conspiracy goes to dust.
You don’t have to be a hacker to create masked files. There are several very simple ways to nest one file within another. For starters, you can use ready-made programs.
One of the solutions is a free program QuickStego for Windows. She can create BMP images with embedded text. You just need to press the buttonOpen Image” to select the original photo. The text in the right field can be entered manually, or you can specify a text file by clicking the “Open Text“. After specifying the desired photo and text, you need to click the “Hide Text” to merge the files. And then – “Save Image” to save the resulting file in BMP format.
The resulting drawing can be viewed and modified in editors. The text will remain untouched. To see it, you need to open the picture through the QuickStego program. The text will be visible in the right margin.
Another option is a free program DeepSound for Windows. It allows you to hide not only texts, but any files in general, using music tracks as containers. It works very simply. Button “Open carrier files” opens music files where you want to hide something, or in which something is already hidden. Button “Add secret files” allows you to select the files you want to hide. Please note that the size of attachments is limited and depends on the size of the music container file and on the sound quality of the output. The longer the audio track and the lower the sound quality, the more files fit inside it. Button “Encode secret files” is used to sew the selected attachments into the container file. Button “Extract secret files” – to extract attachments from a prepared container file. In general, everything is extremely simple.
If you do not want or do not have the opportunity to use ready-made software solutions, you can use the command line.
On Windows, you can only hide text inside pictures using the command line. To do this, take the text file you want to hide (hereinafter – secret.txt) and the picture you want to use as a container (hereinafter – container.jpg). Put both files in the same folder. Click on the address bar in the folder and type “cmd“ (without quotes). A command line window will appear.
In the command prompt window, without quotes, enter the following construction: “copy /b secret.txt + container.jpg hidden.jpg“. Here secret.txt – the file with the text you want to hide, container.jpg – the picture you want to use, and hidden.jpg – name for the new final file with the secret. File hidden.jpg will appear in the same folder. It will look and work like a copy container.jpgbut if you open it through Notepad or any other text editor, you will see your hidden text at the very beginning of the document.
On macOS, you can hide text files or entire zip archives inside pictures. First, put the files you need on your desktop. We will call the archive with secret information secret.zipthe image that will serve as the container – container.jpg.
Next, you need to launch the Terminal application (analogous to the command line in macOS). To do this, activate the Spotlight search with the keyboard shortcut Cmd+Spacethen type “terminal” without quotes and select the desired application.
In the Terminal window, without quotes, type “cd desktop” and press Enter to switch to the desktop. Then, again, without quotes, enter the following construction: “cat container.jpg secret.zip > hidden.jpg“. Here secret.zip and container.jpg – the original secret and container files, and hidden.jpg – the final file with the secret that we are creating.
Now if you try to open hidden.jpg in any graphics editor, it will behave like a normal picture. But if in the Terminal application you enter the command “unzip hidden.jpg”, the image will be unpacked like a regular archive.
If initially instead of the archive you hid a plain text file TXT, then you can read its contents by opening hidden.jpg via TextEdit or any other text editor. The contents of the secret text file will be at the very end of the document.