Steganography is the practice of concealing a file, message, image, or video within another file, message, image, or video. The word steganography comes from the Greek words steganos , meaning "covered, concealed, or protected", and graphein meaning "writing".
With advances in digital technology, steganography has become increasingly popular and easy to use. Images and videos are particularly popular carriers for steganographic content due to their large file size. Common steganographic techniques include least significant bit insertion, masking, and algorithms such as fractal compression.
The least significant bit insertion is the simplest form of steganography and involves replacing the least significant bit of each byte of data with a bit from the message. The result is a slight change in the image that is not perceptible to the human eye. Masking is a more sophisticated technique that involves replacing parts of the carrier image with portions of the message image. The result is an image that looks like the original carrier image, but with a hidden message.
Algorithms such as fractal compression can be used to hide data in the noise of an image. The compression algorithm is used to reduce the file size of the image. The message is then hidden in the resulting noise.
Steganography can be used to hide a message in an image, video, or audio file in order to avoid detection. The advantage of steganography over cryptography is that the existence of the message is not detectable. Even if the message is detected, the content is not accessible without the key.
Steganography is a great way to hide a message in plain sight. With the right tools, anyone can conceal a message in an image, video, or audio file. The challenge is to find a steganographic technique that is undetectable.
As always the ultimate goal of a hacker is to get an access to the victims data without getting knowing them. So they write some spy softwares , scripts or simply viruses which can gain access to the system of the victim. But the problem is that, why do their victims would install that type of softwares or scripts in their systems. so here, Steganography will be one of the the useful technique.Hackers can easily hide their payloads or spy scripts within an ordinary images,files or videos and send it to their victims.
As we know that the cryptography is the process of securing data,information or communications through the use of secret codes so that only those person whom the information is intended can understand it and process it.In this computer age, it is used as like the encryption and decryption.For example:-A person encrypts and sends a message to his friend and his friend recievd it and understand it by decrypting the message.So here the technique used in this whole process can be called as Cryptography.Even there is similar purpose of Steganography and Cryptography, the main difference is that instead of encrypting data like Cryptography, Steganography hides it from the all next users.