Steganography - Types, Techniques, Examples & Applications


Steganography, or the need for hidden messages, is universal since everybody has something confidential. Though it is not such a familiar word as a virus, steganography is crucial since it deals with secrecy. Hiding or withholding information in a standard, national, personal, or family interest is an age-old practice. Cryptography similarly transforms plaintext messages into a jumbled algorithm for safety before sending. The receiver changes it back into plaintext. In Greek, steganography means ‘covered writing’ or ‘disguised messages,’ and nobody knows the hidden meaning.

Cybersecurity requires hidden messages

Isn’t it evident that the secrecy of official or personal messages matters amidst so many cyber criminals these days? While encryption deals with similar disguises, steganography helps, too, with some more significant advantages. Both together help the war against cybercrime and effectively mask messages. Cybersecurity has become absolutely important since the volumes of electronic data have rapidly increased, with so many billions busy sending online messages. As the digital worlds grow, like the critical public infrastructure of services, healthcare and education, manufacturing, and media, it is a cat-and-mouse game with hackers.

Different media hide steganographic messages

During ancient times, so many different media forms did not exist. The 21st century makes wide use of steganography principles. The hidden message can be sent in various forms like text or image. The practice is the same as hidden files attached to the media. Dealing with diverse technology that is constantly improving, novel ways to hide messages are nowadays possible.

  • Text Steganography refers to various media, including text and audio, video, and images. Almost every media form uses text. Data compression through Huffman coding results in a smaller size.

  • Image Steganography hides a message within the image. A cover image is a particular picture that carries a hidden message. A stego image conceals a message that remains secret during transmission. A key is used to embed the messages in the cover and stego images. Sometimes, the images themselves reveal the message.

  • Audio messages can be secretly embedded digitally. Illegal copying of the audio will not be then possible. By watermarking, for instance, one message is superimposed upon another. Media like songs uses such a technique to prevent piracy.

  • Video steganography can include a large volume of messages since it deals with both audio and video in addition to images. Data is embedded, or additional files are inserted inside the video file. DCT, or the Discrete cosine transform method, is often used in the process of hiding data in video images. File formats like H.264 and MP4, along with MPEG and AVI, are often used.

  • Network Steganography uses protocols like TCP and UDP, ICMP, and IP in the task of hiding data as cover objects. Secret channels like OSI make use of such systems.

Technological examples of steganographic disguise

  • An image hidden within a video would be visible only while playing the video at a certain frame rate.

  • A file header or metadata could contain the secret message

  • In an RGB message, the message could be hidden in one of the red, green, or blue channels

  • The primitive form of invisible ink also helps hide a written message very effectively

  • Inserting text in a picture that is somehow disguised in terms of meaning

  • Reverse recording an audio file message

Serving the good and the bad

Common sense indicates that the mighty development of digital media could be used or misused equally well. Used constructively, education and the military benefit from secrecy. Ethical hackers, too, might use the procedures to exchange secret messages. Cybercriminals have access to the same advanced technology to insert malware or damage files and then demand ransomware. One approach is the use of Word documents that use Powershell scripts. When the file is opened, the secret script launches and destroys.

Steganography and Cryptography Compared

Both have similar functions, but which has greater advantages? Steganography is better with messages hidden innocently without calling for attention. Cryptography has a code that attracts attention and announces that some message is hidden. Encrypted data cannot be hidden further from hackers but requires the right key for decryption. In steganography, there is no way of knowing that any secret message is contained in the media. Steganography hides communication, while cryptography makes the message appear nonsensical to protect the data. There is no data visibility in the first, but the second shows the data. The first is not compulsory but elevates security, while the second is a must. Steganography does not change the data structure, but cryptography changes the format. If data is recovered in steganography, anybody can use it. In cryptography, a key is required to open the data package.

Steganography apps achieve the task

How are the secret messages inserted and disguised? Several very effective steganography apps fulfill the task very well. A glance at some of the more successful apps.

  • When the message has to be inserted in an image, Image Steganography uses JavaScript to disguise a picture and hide it in another image file.

  • NoClue is the name of an open-source tool. It can insert and hide textual information in images and videos too.

  • Get familiar with the Android-based and open-source Steganography Master. This app works well to insert hidden text in images. A decoding tool helps to recover the text from the image. The process works on many image formats like BMP, JPG, ICO, and PNG.

  • Trying to hide data in image and audio files works fine with Steghide, including formats like JPEG, BMP, AU, and WAV.

  • OpenStego refers to an open-source app.

  • Xiao Steganography works with WAV and BMP files.

  • Crypture application is the name of a command-line tool.

Conclusion

Massive volumes of electronic data race up and down each day, and many have more than a single recipient, like in social media. It might appear a great mystery how secrecy is maintained amidst the infinite traffic. Despite the most significant efforts to protect messages, cybercrime is constantly increasing, and law enforcement authorities are always busy investigating cases. With great care and some additional time and expense, greater security can be achieved with steganographic techniques through apps. If such procedures are neglected, a heavy price may have to be paid. Not using them is like leaving doors unlocked, and thieves will quickly enter. Steganography is like the safety vaults offered by banks in comparison.

Updated on: 09-Dec-2022

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