Implementation of Least Significant Bit Image Steganography and its Steganalaysis By: Deniz Oran

Goals To conceal either an image or a text message into a "carrier" image with Least Significant Bit Steganography To detect that an image has been compromised or altered To extend the method to apply to various image formats To make the program usable with a Graphical User Interface (GUI)

Literally means "concealed writing" in Greek Opposite of cryptography, in which a message is made unintelligible, but transmitted through public means Steganography is the concealment of the fact that a message is even being transferred. What is Steganography?

Historical Methods Shaving hair Wax tablets Jargon Cardano grille Invisible Inks Micro dots

Current Method Hiding an entire text or image binary in either an image or audio “carrier” using Least Significant Bit encoding Previously done as a Senior Technology Lab using the same technique with.wav audio files in 2007.

Least Significant Bit Encoding Images on computers are made out of pixels Each pixel is represented by three byte s Each byte is composed of eight bits or 1s and 0s The second set of bytes represents the encoded ASCII character “G” ( )

Program Design in JAVA Create a Graphical User Interface dropdown menu encode message or image into a chosen carrier image input a suspected image and attempt to detect if it has been compromised

Inputing the Image Read the binary of the image using Buffered Reader into a two dimensional array (a matrix) Alter every Least Significant Bit in each byte in order to spell out the word. Each ASCII character's binary will have to be specified in a class file. Save the altered image because it is ready to be sent

Steganalysis Detecting steganography is only feasible if the original image is available or if the exact encoding method is known The program will still be able to detect if an image has been compromised by converting the suspected image into hexadecimal Each image format has a specific tag associated with it at a specific part of the hexadecimal code

Image Hex Tags Image FormatTag of Compromised File Location Within the Hex Code.GIF Beginning.JPGFF D9End.PNG E 47 0D 0A 1A 0A D Beginning

Detection Read the suspected image's binary into a text file Convert the binary code into hexadecimal Find the supposed image format of the suspected image Test if its associated hexadecimal tag is legitimate

Possible Problems Steganography is an increasingly complex field because of new algorithms There are many methods to inconspicuously hide an image or text message with computer science, some are less complex (microdots) and some use higher level mathematical algorithms (stochastic modulation) The Least Significant Bit method is an established method and will be probably be detected by commercial Steganalysis software, but not the human eye

Testing Most of the coding so far has been done with binary operations and properly inputting an image into a text file and comprehending pixel values

Learned Concepts How images of various formats are constructed How to manipulate binary code and understanding the role of bits within bytes Various methods of Steganography and Steganalysis and which are the most effective

Future Plans First make the encoding work for one image format Detect that one image format Extend the program to work with other image formats and improve the algorithms susceptibility to common detection methods