a novel method for image steganography with...

International Journal of Advanced Research in Electronics and Communication Engineering (IJARECE)

Volume 3, Issue 11, November 2014

1420

ISSN: 2278 – 909X All Rights Reserved © 2014 IJARECE

A Novel Method for Image Steganography with

Cryptography 1

Mr.R.V. Kiran Kumar M. Tech, 2 *

Mr. T. Kishore Babu,3

Mr.S.Vikrama Teja. 1Associate Professor, RISE PRAKASAM Group of Institutions, ONGOLE, INDIA.

2 * M.Tech RISE PRAKASAM Group of Institutions, ONGOLE, INDIA.

3M. Tech, ONGOLE, INDIA.

Abstract: Now a day’s Steganography plays an important role

in defence, public sectors works and internet. Cryptography

created as a technique for securing the secrecy of

communication and many different methods have been

developed to encrypt, decrypt data in order to keep message

secret .Unfortunately sometimes it may not be enough to keep

the contents of a message secret .It may also be necessary to

keep the existence of the message secret .The technique used to

implement this is called Steganography and it different from

cryptography in the sense cryptography focuses on keeping

contents of a message secret Steganography focuses on keeping

the existence of message secret for more security we proposed

new methods that combines with both cryptography and

Steganography. There are two types of techniques are

implemented, The first technique implemented sequentially

starting with the top left pixel and then encodes information

from top to bottom and left to right, and another techniques

implemented randomly encodes pixel across the entire image in

an attempt to be less noticeable to analysis. These techniques

provide more security for the information with the combination

of image Compression and data encryption and decryption

methods and this methods requires less memory space used as a

compression method to send additional messages with in a

single file and reducing the amount of data to be sent and also

encoding or storing information with the RGB pixels of a cover

image without visual distortion.

keywords: Cryptography, Random encoding Sequential encoding,

Shared secret key Steganography, Stego-image,

I INTRODUCTION

Cryptography which uses a shared secret key, algorithm, or

code to hide the message content from unauthorized access.

Steganography message security relies on its ability to not

be detected while cryptographic message security relies on

its ability to withstand decryption analysis

[3].Cryptography means converting the text from readable

format to unreadable format. But the encrypted text is

visible to all, by applying cryptanalysis on cipher text, the

intruder can get the original message, otherwise he can alter

the cipher text [9].

Figure1. Block diagram for cryptography.

Steganography messages have been concealed using

invisible inks or secret tattoos, but the digital revolution has

provided a rich new area for concealing hidden messages

within the underutilized bits in digital media like image,

video, and music files. Sterganoraphy is also closely related

to, and often uses, cryptography for improved message

security [3]. Steganography is the art and science of

invisible communication. This is accomplished through

hiding information in other information, thus hiding the

existence of the communicated information. The basic

Sterganoraphy model is shown below.



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Figure2. Block Diagram for Steganography.

Today Steganography mostly used on computers with

digital data being the carriers and networks being the high

speed delivery channels [4]. Sequential Encoding or

Decoding is Message Data is Encoded or Decoded from

some starting point Typically upper left pixel and Message

Data is then Encoded or Decoded in a set unvarying pattern

Typically to adjacent pixels and it is Simple to Implement

where as Random Encoding or Decoding Random Number

Generator Initialized typically no set starting point Message

Data is then Encoded or Decoded based upon the

pixel location determined by Random Number Generator

typically no set pattern No set Encoding or Decoding

Pattern for Histogram Analysis to Detect Quicker

Recovery Rate Usually implemented by Pre-Defining

encoding pattern more efficient for recovery process

Message size difficult to estimate[5].

II SYNOPSIS OF STEGANOGRAPHY

Steganography (a rough Greek translation of the term

Steganography is secret writing) has been used in various

forms for 2500 years. It has found use in variously in

military, diplomatic, personal and intellectual property

applications. Briefly stated, Steganography is the term

applied to any number of processes that will hide a message

within an object, where the hidden message will not be

apparent to an observer [2].Synopsis of Steganography are

[1] .

A .Text Steganography

The process is continued by considering the various

positions of the letters. The amount of message that is

hidden in this type is very less and easily recoverable by

frequency of letters. The following are the some of the

methods used frequently by steganographers. Text as a

cover medium is the oldest techniques used in early days.

Secret message is detected by taking the first letter of

every word present in the file. Text hiding in mark-up

languages (HTML), Text Steganography in specific

characters in words, Line shifting method, Word shifting,

Open spaces, Semantic methods, Character encoding [1].

B Image Steganography

Now a day’s people are using various calculations.

Randomly selecting the pixels in the image and replacing

the ASCII values of the text are highly unbreakable

algorithm cryptography and Steganography shakes its

hands together to make the image Steganography robust

.Pictures are attractive to human rather than text Internet

pages are very popular for its pleasant pictures. Human eye

can not notice the changes in the LSB changes of the image.

With this concept images are used to hide the secret

information.

C. Audio Steganography

Steganographers pay their attention in these audio files their

secret message. Digital wave files are used to hide message.

People are hearing the music in their day today life. Free

music downloads from internet through PDA, mobile

phones and pc makes the music files popular. To embed

data secretly onto digital audio there are few techniques

introduced, LSB coding, Phase coding, Parity coding,

spread spectrum.

D. Protocol Steganography

A set of rules used to govern the communication is known

as protocol. TCP, IP, UDP are the some of the protocols

used for communication. Steganographers use this protocol

for hiding their secret data. Some unused parts of the

protocol packet header are efficiently used for message

hiding [6].



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III METHODS OF IMAGE STEGANOGRAPHY

According to the number of bits in a pixel the images

are categorized. One bit per pixel images are monochrome

images. Images are used to hide the message. Two bits

per pixel can display gray scale images. Eight bits per pixel

displays 256 colours of pictures. Twenty four bits per pixel

is known as full colour or true colour system which displays

millions of colours .The following are the some of the

techniques used in image Steganography[1].

A Spatial Domain

Using the eye imperceptions LSB technique is widely used

to hide the message. Pixels are selected either sequentially

or randomly. Encryption of the data and hiding in the LSB

makes Steganography stronger. In spatial domain image

Steganography method pixel values are changed. Least

Significant Bits are changed to hide the secret data. If the

LSB bits are changed the image distortion won’t be noticed

by eye. MSB are also used to hide the data based on the

intensity value. Key also embedded in the image itself so the

intruder finds difficult to recover the text from the image.

B Masking and Filtering

Only gray scale images are used early. In this method MSB

bits are used. Lossy compression images are used

efficiently.

C Transform Domain Technique

Transform domain uses the MSB to hide the data. This

technique is widely used because of its independency over

the image formats [7]. Transform domain is robust than

LSB because it is focused on the image parts that are not

altered by some image editing like cropping, resizing.

Transform domain works well in both lossy and lossless

compression images.

IV PROPOSED TECHNIQUES

Here using Transformation technique as sequential and

random encode and decode methods, the process of

algorithm as shown below as function [output] =

Steganography () then Allow User to Select SEQUENTIAL

or RANDOM Encoding Method and RANDOM ENCODING

needs the Encryption Key AND Random Seed. Determine

Whether User is Encoding or Decoding a Message to

follow two steps those are STEP A: ENCODING VERSION,

STEP B: DECODING VERSION

Figure3. Encoding and decoding step by step

Process diagram

A Encoding process

Figure4. The process of encoding technique

In the encoding process message image contain the secret

data or conceal data and in the combination header and the

message image is encrypted by a simple symmetric

Exclusive OR encryption then the result form is cover

medium + massage.



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B Decoding process

Figure5. The process of decoding technique

In decoding process recovering the hidden message so first

the encrypted header values are recovered from cover

medium image and decrypted using XOR encryption key

used during the encoding process.

C Sequential decoding and encoding

It is a limited memory technique for decoding tree codes.

Sequential decoding is mainly used is as an approximate

decoding algorithm for long constraint-length convolution

codes. This approach may not be as accurate as but can save

a substantial amount of computer memory. Sequential

decoding explores the tree code in such a way to try to

minimize the computational cost and memory requirements

to store the tree[8]. There is a range of sequential decoding

and encoding approaches based on choice of metric and

algorithm. Metrics include Fano metric, Zigangirov metric,

Gallager metric where as Algorithms include Stack

algorithm, Fano algorithm, and Creeper algorithm. In

proposed system using fano algorithm for sequential method

the famous Fano algorithm has a very low memory

requirement and hence is suited to hardware implementations

[12].

.

Figure6. Sequential encoding method

This algorithm explores backwards and forward from a

single point on the tree. The Fano algorithm can only

operate over a code tree because it cannot examine path

merging. Sequential Encoding or Decoding is Message

Data is Encoded or Decoded from some starting

point Typically upper left pixel and Message Data is

then Encoded or Decoded in a set unvarying pattern

Typically to adjacent pixels and it is Simple to

Implement[5].

D Random Encoding and Decoding

It is a process that appears to be random but is not. random

sequences typically exhibit statistical randomness while

being generated by an entirely deterministic causal process.

Such a process is easier to produce than a genuinely random

one, and has the benefit that it can be used again and again

to produce exactly the same numbers - useful for testing and

fixing software. To generate truly random numbers requires

precise, accurate, and repeatable system measurements of

absolutely non-deterministic processes [3].

A randomized algorithm is an algorithm that employs a

degree of randomness as part of its logic. The algorithm

typically uses uniformly random bits as an auxiliary input

to guide its behavior, in the hope of achieving good

performance in the "average case" over all possible choices

of random bits. Formally, the algorithm's performance will

be a random variable determined by the random bits; thus

either the running time, or the outputs are random variables.

One has to distinguish between algorithms that use the

random input to reduce the expected running time or

memory usage, but always terminate with a correct result in

http://en.wikipedia.org/w/index.php?title=Tree_codes&action=edit&redlink=1

http://en.wikipedia.org/wiki/Convolutional_code



http://en.wikipedia.org/wiki/Randomness

http://en.wikipedia.org/wiki/Statistical_randomness

http://en.wikipedia.org/wiki/Deterministic_system

http://en.wikipedia.org/wiki/Algorithm


http://en.wikipedia.org/wiki/Uniform_distribution_(discrete)

http://en.wikipedia.org/wiki/Random_variable



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a bounded amount of time, and probabilistic algorithms,

which, depending on the random input, have a chance of

producing an incorrect result or fail to produce a result

either by signaling a failure or failing to terminate. In the

second case, random performance and random output, the

term "algorithm" for a procedure is somewhat questionable.

In the case of random output, it is no longer

formally effective [10]. However, in some cases,

probabilistic algorithms are the only practical means of

solving a problem [11].

Figure7. Random Encoding method

Random number generator is a program written for, and

used in, probability and statistics applications when large

quantities of random digits are needed. Most of these

programs produce endless strings of single-digit numbers,

usually in base 10, known as the decimal system. When

large samples of random numbers are taken, each of the 10

digits in the set {0,1,2,3,4,5,6,7,8,9} occurs with equal

frequency, even though they are not evenly distributed in

the sequence. Algorithm has been developed in an attempt

to produce truly random sequences of numbers, endless

strings of digits in which it is theoretically impossible to

predict the next digit in the sequence based on the digits up

to a given point. But the very existence of the algorithm, no

matter how sophisticated, means that the next digit can be

predicted! This has given rise to the term pseudo-random

for such machine-generated strings of digits [3].

V RESULT

Figure8.Sequential encoding Steganography function

Figure9.SequentialdecodingSteganography function

http://en.wikipedia.org/wiki/Effective_method

http://whatis.techtarget.com/definition/algorithm



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Figure10.Random encoding steSteganography function

Figure11.Randomdecoding Steganography

Function

Figure12. Original images Figure 13.Stego images

VI CONCLUSION

Steganography using MATLAB and two methods carries this

paper in that first method Sequential decoding and encoding

is a limited memory technique for decoding tree codes,

explores backwards and forward from a single point on the

tree. The algorithm can only operate over a code tree.

Message Data is then Encoded or Decoded in a set unvarying

pattern Typically to adjacent pixels and it is Simple to

Implement but Easily Detected using Histogram Analysis,

Slow and Tedious Recovery where as second method is

Random Encoding and Decoding is a process that appears to

be random but is not. No set Encoding or Decoding Pattern

for Histogram Analysis to Detect, Quicker Recovery Rate but

Detectable using varying sized windows and localized

Histogram Analysis.

VII REFERENCES

[1].http://www.enggjournals.com/ijet/docs/IJET13-05-02-0

34.pdf study on image steganography techniques C. Gayatri,

V. Kalpana computer science & engineering, school of

computing SASTRAUNIVERSITY,Timalaisamudram.

http://en.wikipedia.org/w/index.php?title=Tree_codes&action=edit&redlink=1


http://www.enggjournals.com/ijet/docs/IJET13-05-02-034.pdf






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[2].http://www.sans.org/reading-room/whitepapers/stengan

ography/steganography-past-present-future-552

[3].http://en.wikipedia.org/wiki/Pseudorandomness ‎

[4]. Moerland,‎ T.,‎ “Steganography and‎ Steganalysis”,‎

Leiden Institute of Advanced Computing

Science,www.liacs.nl/home/ tmoerl/privtech.pdf

[5].https://sites.google.com/site/cs534steganographyproject

/home/2-sequential-vs-pseudo-random-encoding-decoding

[6].Vijay kumar sharma, Vishal srivastava “A‎

steganography Algorithm for hiding image in image by

improved‎lsb‎substitution‎by‎minimize‎detection”‎journal‎of‎

theoretical and applied information technology 15th

february 2012. vol. 36 no.1

[7] .Dr. Ekta Walia a, Payal Jain “An‎Analysis‎of‎LSB‎&‎

DCT‎based‎Steganography“,Global‎Journal‎of‎Computer‎

Science and Technology, 4 Vol. 10 Issue 1 (Ver 1.0), April

2010,

[8].http://en.wikipedia.org/wiki/Sequential_decoding.

[9].‎R‎Praveen‎Kumar‎and‎V‎Hemanth,‎Mshareef,‎“Securing‎

Information‎Using‎Steganography”,‎International

Conference on Circuits, Power and Computing

Technologies, 2013.

[10] Henri Cohen (2000). A Course in Computational

Algebraic Number Theory. Springer-Verlag, p. 2.

[11]. HalAbelson and GeraldJ.Sussman (1996). Structure

and Interpretation of Computer Programs. MIT

Press, section 1.2

[12]http://en.wikipedia.org/wiki/Sequential_decoding#Fan

o_algorithm://en.wikipedia.org/wiki/Special:BookSources/

0262230062.

Mr.R.V. Kiran Kumar working as a Associate

Professor in ECE Dept, RISE PRAKASAM Group of Institutions

.He had completed B.Tech in ECE and M.Tech in DECS. He had 8

years of teaching experience and he is working as a Head of the

Dept of ECE. His area of specialization in Digital signal processing

,Signals and System, Digital Image Processing, Radar System,

Advanced digital Signal Processing and cellular and mobile

Communication.

Mr.T.Kishore Babu has obtained B.Tech with

specialization of Electronics and communication Engineering from

Prakasam Engg. College,Kandukur,Andhrapradesh and currently

pursuing M.Tech with specialization of Digital Electronics and

Communication Systems in RISE PRAKSAM Group of

Institutions,Ongole ,Andhrapradesh,India.

Mr.S.Vikrama Teja Received B.Tech Information

Technology in PrakasamEngg,College, Kandukur, Andhrapradesh

,India and Received M.Tech with specialization of Computer

Science And Engineering in QIS College of Engineering and

Technology,Ongole,India.

http://www.sans.org/reading-room/whitepapers/stenganography/steganography-past-present-future-552

http://www.sans.org/reading-room/whitepapers/stenganography/steganography-past-present-future-552

http://en.wikipedia.org/wiki/Pseudorandomness

https://sites.google.com/site/cs534steganographyproject/home/2-sequential-vs-pseudo-random-encoding-decoding



https://www.google.co.in/search?espv=2&biw=1024&bih=559&q=%5B2%5D+Vijay+kumar+sharma,+Vishal+srivastava+%E2%80%9CA+steganography+Algorithm+for+hiding+image+in+image+by+improved+lsb+substitution+by+minimize+detection%E2%80%9D+journal+of+theoretical+and+applied+information+technology+15th+february+2012.+vol.+36+no.1&spell=1&sa=X&ei=mLpMVOXiI-S4mAW6voLwAw&ved=0CBgQBSgA





https://www.google.co.in/search?es_sm=93&q=%5B3%5D+Dr.+Ekta+Walia+a,+Payal+Jain+%E2%80%9CAn+Analysis+of+LSB+%26+DCT+based+Steganography%E2%80%9C,Global+Journal+of+Computer+Science+and+Technology,+4+Vol.+10+Issue+1+(Ver+1.0),+April+2010,&spell=1&sa=X&ei=VrpMVOj7LoLAmwXP8IDIBA&ved=0CBoQBSgA






CJK

CJK

http://en.wikipedia.org/wiki/Hal_Abelson

http://en.wikipedia.org/wiki/Gerald_J._Sussman

http://en.wikipedia.org/wiki/Structure_and_Interpretation_of_Computer_Programs



http://en.wikipedia.org/wiki/MIT_Press



http://mitpress.mit.edu/sicp/full-text/book/book-Z-H-11.html#footnote_Temp_80

http://en.wikipedia.org/wiki/Sequential_decoding#Fano_algorithm





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