What is Steganography?
Steganography is the technique of hiding a secret message inside (or even on top of) something that is not secret. That something can be anything you want. Today, many examples of steganography involve embedding secret text into images. Or hide secret messages or scripts in Word or Excel documents.
The purpose of steganography is to hide and deceive. This is a form of covert communication and may use any medium to hide the message. It is not a form of encryption as it does not involve encrypting data or using keys. Instead, it’s a form of data obfuscation that can be done in clever ways. Steganography is a practice that allows for confidentiality and deception, while cryptography is a science that allows for greater privacy.
Steganography has been around for centuries, but these days hackers and IT professionals are digitizing it and doing some pretty creative things. There are many apps available for steganography such as Steghide, Xiao, Stegais, Concealment.
The word steganography may seem fancy, but it actually comes from a fairly ordinary place. The root “steganos” means “hidden” or covered in Greek, and the root “graph” means “to write” in Greek. Combining these words gives something like ‘hidden writing’ or “secret writing”.
The various techniques used are:
A. Character Marking: Selected letters are overwritten in pencil. The marks are ordinarily not visible unless the paper is held at an angle to bright light.
B. Invisible Ink: A number of substances can be used for writing but secure trace until some other chemical is applied to the paper.
C. Pin Punctures: Small pin punctures on the pictures are ordinarily not visible unless the paper is held up in front of a light.
D. Subset Method: In this method subset of the words of the overall message is used to convey the hidden message.
Disadvantages/ Drawbacks compared to Encryption:
- It requires a lot of overhead to hide a relatively few bits of information.
- Once the system is discovered it becomes totally useless.
