Lossless Compression and Information Hiding in Images Using Steganography

8/11/2019 Lossless Compression and Information Hiding in Images Using Steganography

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1. Lossless Compression and information hiding in images using

Steganography

Abstract:

In this paper a novel method is proposed to provide more security for the key

information with the combination of image compression and data encryption method.

This method requires less memory space and fast transmission rate because of image

compression technique is applied. Steganography plays an important role in information

security. It is the art of hiding the fact that communication is takes place, by hiding

information in other information. Many different file formats can be used. For hiding

secret information in images, there exist a large variety of stenographic techniques

some are more complex than others and all of them have respective strong and weak

points. Many applications have different requirements of the steganography technique

used. Some applications may use absolute invisibility of the secret information, but

others require a larger secret message to be hidden. This method has been implemented

and tested on varies images and data. It provides better security for encrypted data and

no distortion in the image quality.

Existing System

There are a large number of steganographic methods that most of us are familiar

with, ranging from invisible ink and microdots to secreting a hidden message in the

second letter of each word of a large body of text and spread spectrum radio

communication. With computers and networks, there are many other ways of hiding

information, such as:

Covert channels (e.g., Loki and some distributed denial-of-service tools use the

Internet Control Message Protocol, or ICMP, as the communications channel between the

"bad guy" and a compromised system)

Hidden text within Web pages

Hiding files in "plain sight" (e.g., what better place to "hide" a file than with an

important sounding name in the c:\winnt\system32directory?)

Null ciphers (e.g., using the first letter of each word to form a hidden message in an

otherwise innocuous text)

Steganography today, however, is significantly more sophisticated than the

examples above suggest, allowing a user to hide large amounts of information within

image and audio files. These forms of steganography often are used in conjunction with


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cryptography so that the information is doubly protected; first it is encrypted and then

hidden so that an adversary has to first find the information (an often difficult task in

and of itself) and then decrypt it.

Disadvantages

Normally must use the original program to hide and reveal data

If the picture with the hidden information is converted to another format, then the

hidden data may be lost.

Proposed System

To a computer, an image is a collection of numbers that constitute different light

intensities in different areas of the image. The numeric value representation forms a grid

and the individual points are referred to as pixels. Image is the most popular cover

objects used for steganography. In the domain of digital images many different image

file formats exist, most of them for specific applications. For these different image file

formats, different stenographic algorithms exist. Image steganography techniques can

be divided into two groups: those in the Image Domain and those in the Transform

Domain. Image also known as spatial domain techniques embed messages in the

intensity of the pixels directly, while for

Transform also known as frequency domain, images are first transformed and then

the message is embedded in the image. Image domain techniques encompass bit-wisemethods that apply bit insertion and noise manipulation and are sometimes

characterized as simple systems. The image formats that are most suitable for image

domain steganography are lossless and the techniques are typically dependent on the

image format. Steganography in the transform domain involves the manipulation of

algorithms and image transforms. These methods are used to hide messages in more

significant areas of the image, making it more robust. Many transform domain methods

are independent of the image format and the embedded message may survive

conversion between loss and lossless compression.

Advantages

Main purpose of steganography is to provide secret communication


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Steganography has the advantage that even a talented code-cracker cannot decipher

a message without knowing it is there.

Steganography is beneficial for securely storing sensitive data, such as hiding system

passwords or keys within other files.

Data Flow Diagram:

Embedded file:

Compressed

Retrieve File:

Project Description:

The simplest approach to hiding data within an image file is called Least

Significant bit (LSB) insertion. In this method, we can take the binary

representation of the hidden data and overwrite the LSB of each byte within

the cover image. If we are using 24-bit color, the amount of change will be

minimal and indiscernible to the human eye. As an example, suppose that

we have three adjacent pixels (nine bytes) with the following RGB

encoding:

10010101 00001101 11001001

10010110 00001111 11001010

Master

Using Public Compressed fileoutput file

Data file

Retrieve

Data fileView DataUsing PublicCompressed file


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10011111 00010000 11001011

Now suppose we want to "hide" the following 9 bits of data (the hidden data is

usually compressed prior to being hidden): 101101101. If we overlay these 9 bits

over the LSB of the 9 bytes above, we get the following (where bits in boldhave

been changed):

10010101 0000110011001001

100101110000111011001011

10011111 00010000 11001011

Note that we have successfully hidden 9 bits but at a cost of only changing 4, or

roughly 50%, of the LSBs.

The following formula provides a very generic description of the pieces of the

steganographic process:

Cover medium + hidden data + stego_key = stego_medium

In this context, the cover medium is the file in which we will hide the hidden

data, which may also be encrypted using the stego key. The resultant file is the

stego medium (which will, of course. be the same type of file as the cover

medium). The cover mediums (and, thus, the stego_medium) are typically

image or audio files. In this article, I will focus on image files and will,

therefore, refer to the cover image and stego image.


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Software Requirements:

Operating System : Windows XP

Front End : Java Swing

Programming tool : net beans

Hardware Requirements:

Processor : Intel Pentium IV

Cache Memory : 1MB

HDD : 40 GB

RAM : 512 MB

Processor Speed : 600 MHz

Display Type : VGA

Mouse : Logitech


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Monitor : 15 Samsung Color Monitor

Documents

Lossless Compression and Information Hiding in Images Using Steganography