security:steganography
Differences
This shows you the differences between two versions of the page.
Both sides previous revisionPrevious revisionNext revision | Previous revisionLast revisionBoth sides next revision | ||
security:steganography [2011/11/21 12:27] – [Steganalysis of the LSB method] cedric | security:steganography [2016/07/05 13:01] – cedric | ||
---|---|---|---|
Line 1: | Line 1: | ||
+ | ====== Installation of Stéganô ====== | ||
+ | |||
+ | For the examples you need to install Stéganô. | ||
+ | |||
+ | <code bash> | ||
+ | sudo pip install Stegano | ||
+ | </ | ||
+ | |||
+ | You can read the [[http:// | ||
+ | |||
====== Steganography ====== | ====== Steganography ====== | ||
Steganography is the art and science of writing hidden messages. | Steganography is the art and science of writing hidden messages. | ||
Line 10: | Line 20: | ||
We will dive into digital steganography. | We will dive into digital steganography. | ||
- | The folowing | + | The following |
===== Simple steganography art ===== | ===== Simple steganography art ===== | ||
- | In computer | + | In computer |
For example, if I want to hide a text file in a music file: | For example, if I want to hide a text file in a music file: | ||
Line 132: | Line 142: | ||
This technique simply consist to replace odd components by 255 and even number by 0. This means that the pixel (132, 247, 123) become (0, 255, 255). | This technique simply consist to replace odd components by 255 and even number by 0. This means that the pixel (132, 247, 123) become (0, 255, 255). | ||
+ | |||
+ | |||
+ | ===== Steganalysis of the LSB method with sets ===== | ||
+ | You must [[security: | ||
+ | |||
+ | First, we will hide a message in a picture with the simple LSB method and with the LSB method + sets. | ||
+ | |||
+ | <code bash> | ||
+ | $ cd stegano | ||
+ | |||
+ | # LSB with The Eratosthenes set | ||
+ | $ slsb-set --hide -i ./ | ||
+ | |||
+ | # LSB only | ||
+ | $ slsb --hide -i ./ | ||
+ | </ | ||
+ | |||
+ | The selected generator //Sieve of Eratosthenes// | ||
+ | |||
+ | The following will generate the corresponding steganalysed pictures (left column): | ||
+ | <code bash> | ||
+ | # Steganalysis of the original image | ||
+ | $ steganalysis-parity -i ../ | ||
+ | |||
+ | # Steganalysis of the image with hidden text (LSB only) | ||
+ | $ steganalysis-parity -i ~/ | ||
+ | |||
+ | # Steganalysis of the image with hidden text (LSB + Eratosthenes) | ||
+ | $ steganalysis-parity -i ~/ | ||
+ | </ | ||
+ | |||
+ | |||
+ | {{: | ||
+ | {{ : | ||
+ | |||
+ | |||
+ | {{: | ||
+ | {{ : | ||
+ | |||
+ | {{: | ||
+ | {{ : | ||
+ | |||
+ | |||
+ | Compare the pictures 1 and 2 and compare the pictures 1 and 3, left column. | ||
+ | |||
+ | ==== Reveal the message ==== | ||
+ | <code bash> | ||
+ | $ slsb-set --reveal --generator eratosthenes -i ~/ | ||
+ | $ slsb --reveal | ||
+ | $ cmp ~/ | ||
+ | $ cat ~/ | ||
+ | Lorem ipsum dolor sit amet, consectetur adipiscing elit. Nam placerat fermentum | ||
+ | lorem, at porttitor metus congue eu. Mauris vitae tell | ||
+ | . | ||
+ | . | ||
+ | . | ||
+ | $ slsb-set --reveal --generator fermat -i ~/ | ||
+ | Impossible to detect message. | ||
+ | |||
+ | $ slsb-set --reveal --generator mersenne -i ~/ | ||
+ | Impossible to detect message. | ||
+ | </ | ||
+ | |||
+ | |||
+ | |||
+ | |||
====== Bibliography ====== | ====== Bibliography ====== | ||
security/steganography.txt · Last modified: 2021/06/27 00:36 by cedric