DIGITAL ENCRYPTION THROUGH
STEGNOGRAPHY
MAHIMA SHARMA, MOKSHI GUPTA
Email id: anjali.sharma3610@gmail.com, gupta21mokshi@gmail.com
Department of Computer Science and Engineering, Raj Kumar Goel Institute of Technology for
Women,
Ghaziabad, Uttar Pradesh, India
ABSTRACT: In modern world, in any of the
various communication methods available, security
is the most important issue. For the safety of the
signal we use Steganography, to hide the data or
message we have various techniques in different
domains like spatial domain, frequency domain etc.
In frequency domain it is very difficult to detect
hidden message and for this domain we use various
transformations like DCT, FFT and Wavelets etc.
In this project we are developing a system in which
two techniques, steganography and cryptography
are combined, which provides a strong backbone
for its security. In present day information security
system various features like confidentiality,
authenticity, integrity, non-repudiation etc. are a
must. This present work focus is enlightening the
technique to secure data or message with
authenticity and integrity. In this project work,
before the starting of the embedding process the
secret message is encrypted already. We use Tiny
algorithm using secret key for and DCT technique
is used for embedding and extraction file.
reveal the information to others, modify it to
misrepresent an individual or organization, or use it
to launch an attack. One solution to this problem is,
through the use of steganography. Steganography is
a technique of hiding information in digital media.
In contrast to cryptography, it is not to keep others
from knowing the hidden information but it is to
keep others from thinking that the information even
exists.
Steganography become more important as more
people
join
the
cyberspace
revolution.
Steganography is the art of concealing information
in ways that prevents the detection of hidden
messages. Steganography include an array of secret
communication methods that hide the message from
being seen or discovered.
KEYWORDS: Steganography, Cryptography,
Encryption, Data hiding.
Due to advances in ICT, most of information is kept
electronically.
INTRODUCTION: One of the reasons that
intruders can be successful is the most of the
information they acquire from a system is in a form
that they can read and comprehend. Intruders may
Consequently,
the
security
of
information has become a fundamental issue.
Besides
cryptography,
steganography
can
be
employed to secure information. In cryptography,
the message or encrypted message is embedded in a
digital host before passing it through the network,
thus the existence of the message is unknown.
Besides hiding data
for confidentiality, this
approach of information hiding can be extended to
copyright protection for digital media: audio, video
and images.
The
growing
possibilities
of
modern
communications need the special means of security
especially on computer network. The network
security is becoming more important as the number
of data being exchanged on the internet increases.
THE PROPOSED
SYSTEM
In this proposed system we have the software for
data encryption and then embed the cipher text
in a cover medium. The combination of effect of
these two methods is achieved which enhances
the security of the data.
In the proposed system the data is encrypted
with a tiny algorithm and then the encrypted
data is embedded in a cover file using DCT
algorithm. This system improves the security of
the data by embedding the encrypted data and
not the plain data in cover file. The block
diagram of proposed system is as shown in
fig.1
Therefore, the confidentiality and data integrity are
requires to protect against unauthorized access and
use. This has resulted in an explosive growth of the
field of information hiding Information hiding is an
emerging
research
area,
which
encompasses
applications such as copyright protection for digital
media,
watermarking,
fingerprinting,
and
steganography.
In watermarking applications, the message
contains information such as owner identification
and a digital time stamp, which usually applied for
copyright protection.
Fingerprint, the owner of the data set
embeds a serial number that uniquely identifies the
user of the data set. This adds to copyright
Fig. 1 Block diagram of proposed
system
information to makes it possible to trace any
unauthorized used of the data set back to the user.
Steganography hide the secrete message
within the host data set and presence imperceptible
and is to be reliably communicated to a receiver.
The host data set is purposely corrupted, but in a
covert way, designed to be invisible to an
information analysis.
Two distinct methods are used to embed a
secret message file in the cover file:
(1) Encrypt the secret
message
(2) The encrypted secret message is embed in the
cover media.
A. Encryption
algorithm
In this encryption method only receiver and
sender knows secret key thus it is simple and
efficient and is of symmetric type. The Secret
key length is variable and is of range double
precision. At the receiver side during extraction
process the decryption, that is the reverse
process of encryption is carried out using the
same key to obtain the secret message from
stegno medium. The reason for which the
message is encrypted is:
Cryptography + Steganography = Secure
Steganography
1)
Crypto
module
Text File + Tiny Algorithm = Encrypted File
2)
Stegno
module
Encrypted File + DCT Algorithm + Stegno
medium = Stegno Object
Basically, the model for steganography is shown on
following figure:
Coverobject, C
F(X,M,K)
Message, M
Stego Object, Z
Stego-key,
K
Fig. 2 Stego object
1) Tiny
Algorithm
Tiny Encryption Algorithm the Tiny Encryption
Algorithm is a Feistel type cipher (Feistel, 1973)
that uses operations from mixed (orthogonal)
algebraic groups XOR, ADD and SHIFT. A dual
shift causes all bits of the data and key to be mixed
repeatedly. The key schedule algorithm is simple;
the 128-bit key K is split into four 32-bit blocks K
= ( K[0], K[1], K[2], K[3]). TEA seems to be
highly resistant to differential cryptanalysis
(Biham et al., 1992) and achieves complete
diffusion (where a one bit difference in the
plaintext will cause approximately 32 bit
differences
in the
cipher
text). Time
performance on a workstation is very impressive.
2) Encryption
Routine
The Encrypt Routine is written in the C
language and assumes a 32-bit word size. The 128
bit key is split into four parts and is stored in k[0] k [3] and the Data is stored in v[0] and v[1].
Void code(long* v,
long* k) {
Unsigned long y = v[0], z = v[1], sum = 0,
/* set up */
Delta = 0x9e3779b9, n = 32; /* a key schedule
constant */
While (n-->0) {/* basic cycle
start */
Sum
+=
delta;
y += (z<<4)+k[0] ^ z+sum ^
(z>>5)+k[1];
z += (y<<4)+k[2] ^ y+sum ^ (y>>5)+k[3]; /*
end cycle */
}
v[0] = y ; v[1] = z
;}
The constant delta is given as delta = (√5 -1)
* 231 i.e.
9E3779B9h and is derived from the golden
number ratio to ensure that the sub keys are
distinct and its precise value has no
cryptographic significance.
TEA uses addition and subtraction as the
reversible operators instead of XOR. The TEA
encryption routine relies on the alternate use of
XOR and ADD to provide nonlinearity. The
algorithm has 32 cycles (64 rounds). TEA is short
enough to write into almost any program on any
computer.
The Tiny Encryption Algorithm (TEA) is a block
cipher encryption algorithm that is very simple
to implement, has fast execution time, and takes
minimal storage space [2].
B.Embedding
algorithm
1)Discrete Cosine transform
(DCT)
According to the method presented in this paper,
in the DCT domain of the host image the message
is inserted. The hidden message is a stream of
“1” and “0” giving a total number of 56 bits. The
transform is applied to the image as a multiple
factor of 8x8 blocks. The next step of the
technique after the DCT is to select the 56 larger
positive coefficients, in the low-mid frequency
range.
The
high
frequency coefficients
represent the image details and are vulnerable to
most common image manipulation like filtering
[11] compression [12] etc. Our scheme is applied
to the whole image and the low and mid
frequency coefficients are the most appropriate
because robustness is the main issue. The selected
coefficients ci are ordered by magnitude and
then modified by the corresponding bit in the
message stream. If the ith message bit s(i) to be
embedded is “1”, a quantity D is added to the
coefficient. This D quantity represents the
persistence factor. If the message bit is “0”, the
same quantity is subtracted from the coefficient.
Thus the replaced DCT coefficients are
DCT (new) = DCT+1*D for
s(i)=1; Else
DCT (new) =DCT-1*D for
s(i)=0.
DCT can separate the image into High, Middle and
Low Frequency components. We need to set a
threshold value to hide information for the DCT
coefficients, depending on the quality of the
images.
from stegomedium and then press decrypt button
to get the original file which is in readable form.
And press exit button to get out of the home
window.
Same secret key is required at the time of
encryption at sender side and the at the receiver
side at the time of decryption of file or dembeded
the file. Secret key must be known to both sender
and receiver. If the incorrect key is entered it is
not possible to recover the message.
As our eye is not very sensitive so therefore after
embedding a secret message in a cover file our
eye may not be able to find the difference
between the original message and the message
after inserting some secret text or message on to
it.
SUMMARY:
Steganography is a really
interesting subject and outside of the mainstream
cryptography and system administration that most
of us deal with day after day.
Steganography can be used for hidden
communication. We have explored the limits of
steganography theory and practice. We printed out
the enhancement of the image steganography
system using LSB approach to provide a means of
secure communication. A stego-key has been
applied to the system during embedment of the
C. Description
Proposed Work
of
During the execution of the system, GUI is
displayed for login window, from where the user
can login to enter into the system and new user can
register himself. The system has an option of
forgot password, in case if any registered user
forget his password. Database is provided to store
user ids and passwords. The system provides the
process for encryption, decryption, embedding,
and de-embedding. The Encryption window
provides option for selecting secret message
file, for this system the secret message file is
text file. Embedding window to embed the
message in cover file to get stegomedium
and the press save button to save the stegomedium.
In Home window press dembedd button in
home window to extract the secret message
message into the cover image.
This steganography application software provided
for the purpose to how to use any type of image
formats to hiding any type of files inside their. The
master work of this application is in supporting any
type of pictures without need to convert to bitmap,
and lower limitation on file size to hide, because of
using maximum memory space in pictures to hide
the file.
Since ancient times, man has found a desire in the
ability to communicate covertly. The recent
explosion of research in watermarking to protect
intellectual property is evidence that steganography

MCAD/MCSE/MCDBA Self-Paced
is not just limited to military or espionage
Training Kit: Microsoft SQL Server 2000
applications. Steganography, like cryptography, will
Database Design and Implementation, Exam
play an increasing role in the future of secure
70-229, Second Edition
communication in the “digital world”.
FUTURE WORK: As future
work,
we
intend to study more steganalytic techniques
i.e. detecting whether a particular file contains any
form of embedding or not. We also plan to extend
our system so that it can hide digital files in
other digital files, for example hiding Audio
files in Videos files etc.
REFRENCES: Websites
Following websites are referring to create this
project reports.

http://www.google.com

http://www.microsoft.com

http://www.wikipedia.org

http://projectabstracts.com
Books
Following books and eBook are used to complete
this project reports.

Mastering C# (Paperback)

SQL Server Bible (Paperback)

.NET Black Book (Paperback)

Professional C#, 2nd Edition (Paperback)

Professional ASP.NET (Paperback)

MCAD/MCSD Self-Paced Training Kit:
Developing Web Applications with
Microsoft® Visual Basic® .NET and
Microsoft Visual C#® .NET, Second
Edition