Intro to Steganography

3 min readOct 4, 2023

Steganography is a technique of hiding secret information within an ordinary-looking file or message to avoid detection. The hidden data can be extracted at its destination, and it can be used to conceal almost any type of digital content, including text, image, video, or audio content. The content to be concealed through steganography is often encrypted before being incorporated into the innocuous-seeming cover text file or data stream. Steganography is being used for both constructive and destructive purposes, including concealing and delivering more effective cyber-attacks, referred to as Stegware.

In this article we will go through some basic techniques and tools.

LSB Steganography

It is a technique used to hide information within digital images or other media by altering the least significant bits.

In the case of images, an image is made up of pixels and each pixel is a triplet (red,green,blue).

R,g,b’s values can range anywhere from 0 to 255. It is an 8-bit number, and the value corresponds to intensity of the colour. Changing the MSB has massive effects, and it is the opposite with LSB’s that’s the reason they are preferred for steganography.

There are many tools to perform LSB steganography both command line and web-app.

StegOnline (georgeom.net) is a good web-based image steganography tool as it has many options like choosing the bits, whether MSB or LSB and direction.

Steghide

It is a command tool, and it can be used to hide data in bmp jpeg, wav and au files. It also supports encryption and passphrase mechanisms.

Stegolsb wavsteg

Stegolsb wavsteg is specifically for .wav files. In image we saw the concept of pixels similarly .wav file consists of audio samples and each audio sample is a numerical value representing the loudness. Similarly changing the LSB of an audio sample would not make much difference.

Stegsnow

This falls under whitespace steganography, in white space steganography messages are concealed by adding whitespaces. Encryption can be used so that even if the message is found it can’t be understood.