Steganography was a very uncommon and unique sub discipline in Information Security. It is unlike their famous cousin, Cryptography – always gets the spotlight. Yup, it even gets the most credit in many well-known Hollywood movies. I am sure that almost everyone has watched the Da Vinci Code movie, am I right?
14 years ago, It is a year I decide to pursue my Master of Science by research. I met my supervisor, Professor Ramlan Mahmod, and voiced out my intention. When I proposed this topic to him, it was such a nerve-breaking feeling. Why? Steganography is such a baby area (in Malaysia), and this field does not have much expertise in Malaysia. His PhD student and I were the pioneers for this field in UPM.
Nevertheless, I took it as a challenge ^^, and I signed an agreement to complete the research till PhD. There was no U-turn for this agreement~ haha. Yet, I never regret it.
What is this so unfamiliar jargon? Let’s dig deeper.
Steganography is an art of science which existed a long time ago, before the century. But it was not in the Dinosaur era ya, of course. The word Steganography was derived from ancient Greek. Stegano means hiding, and graphy means images. Therefore, the meaning of Steganography brings to “hide into an image”. Surprisingly, this method is commonly used for military purposes.
Throughout history, Steganography was used to send a secret message and to have a secret communication. The first example of this ancient technique was used by a Greek general who wrote confidential information on the shaved head of a trusted messenger and sent him to the receiver once his hair had fully grown back to hide the message completely.
This technique has crossed my mind, which during my childhood, I had a sort of similar secret communication role play. We used lime juice ink, refilled the ink pen, and then wrote a secret message on a piece of white paper. If you look into it with naked eyes, the paper appears to be blank – nothing was written there. However, if you hold it up under the sun and see through it, the written secret message will appear. Aha! Things are getting more exciting, right? 🙂
These are some stories from the past that I want to share, which are related to Steganography in the force and military area:
The technique has evolved over time, and during World War 2, the German army used invisible ink to write secret information in their covert communications. The fundamental of steganography elements comprises a secret message and a cover medium in which various techniques are used to embed the former into the latter. The steganography media will be the result of the combination between the secret message and the cover medium. Then, the secret communication is completed by sending the steganography media to the other parties with a key or technique to reveal the secret message. Only the recipient knows the keys or the technique used to conceal the secret message. On the other hand, the stego object has to have a high degree of perceptual transparency not to raise any public suspicion during transmission. [1]
Today in the digital era, the medium for hiding the secret message has been digitalized. Secret communication is now in the form of multimedia. It can be digital text, images, sound (audio) or even animation (video). The most popular technique is hiding digital text into digital images by using a specific algorithm. This is what we call the beauty of art and science 🙂
The following figure is to illustrate the basic diagram for the new modern Steganography simply.
However, what the difference between steganography and cryptography? Read over my next posting for more eureka information!
See you! Bye 🙂
References: N.A Roslan, 2018, “Character Properties Method with Biometric Multifactor Authentication for Arabic Text Steganography”, Doctor of Philosophy, Universiti Putra Malaysia