A SYSTEM FOR SECURED STEGANOGRAPHY IN ENCRYPTED IMAGES

Abstract

The present disclosure relates to a system for reversible data hiding encrypted images. The disclosure presents RDH in an encrypted cover image. Embedding of information is done on the pivot pixels of the interpolated image. The experiment is conducted on image size of 512 *512 gray scale and color images. The experiment is evaluated using the MA TLAB software with randomly generated bits as the message to be embedded. Each bit of message is embedded using plus/minus one embedding mechanism. The embedding is performed in the encrypted image after interpolation. The experimental results have proved its efficacy by allowing a payload of up to 4 bpp. The Result shows that the proposed method is no where comparable with the existing techniques. This is possible because of embedding not done using conventional expansion techniques.

Specification

PREAMBLE TO THE DESCRIPTION

THE FIELD OF INVENTION

The present disclosure relates to a system for reversible data hiding in encrypted images ..
BACKGROUND OF THE INVENTION
RDH is a technique in which the secret message is extracted and also the cover signal is recovered
completely without a single bit error. Most of the early works in RDH were carried out in
compressed domain, spatial domain and frequency domain. But, necessity for RDH has emerged
with the internet technology getting developed rapidly and cloud storage functions. Lot of images
need to be uploaded on to a cloud server, followed by the embedding of message and also other
processing steps. The data should not be manipulated by the CP, mainly when it comes to private
and most sensitive data like medical reports or images and military images which relate to national
security. In order to make the data secure, RDH in encrypted domain has emerged. More research
have been carried out to maximize the payload and to ensure security. The existing RDH in
encrypted images (RDHEI) can be mainly divided into two categories: One is Vacating Room
Before Encryption (VRBE) where the embedding is performed initially on the cover image and
encryption mechanism is done later and the second is Vacating Room After Encryption in which
the encryption is carried out on the cover image first, later embedding is performed on the encrypted
image.
However, to ensure the safety and security of electronic files, date must be recorded and stored in
the encryption domain during the cloud storage mechanism where the user does not permit the cloud
provider (CP) to access the information and the CP must insert extra information in the data. Hence
Reversible Data Hiding in Encryption domain (RDHE) techniques has emerged. Therefore in order
to avoid the aforementioned drawback there is a need for a system for reversible data hiding in
encrypted images.
SUMMARY OF THE INVENTION
The present disclosure relates to a system for reversible data hiding in encrypted images. The
present disclosure presents RDH in an encrypted cover image. Additional columns are interpolated
into the encrypted image to preserve the information required for reversibility. Embedding of
information is done on the pivot pixels of the interpolated image. Each bit of message is embedded
using plus/minus one embedding mechanism. The experimental results have proved its efficacy by
allowing a payload of up to 4 bpp. The comparison metric shows that the proposed method is no
where comparable with the existing techniques.


COMPLETE SPECIFICATION
Specifications
These and other features, aspects, and advantages of the present disclosure will become
better understood when the following detailed description is read with reference to the
accompanying drawings in which like characters represent like parts throughout the
drawings, wherein:
Figure 1 illustrates a block diagram of a system for reversible data hiding in
encrypted images in accordance with an embodiment of the present disclosure;
Figure 2 illustrates a flow chart of a method for reversible data hiding m
encrypted images in accordance with an embodiment of the present disclosure;
Figure 3 illustrates the General block diagram of RDH in encrypted image in
accordance with an emb()diment of the present disclosure;
Figure 4 illustrates the Block diagram of proposed embedding and extraction in
accordance with an embodiment of the present disclosure;
Figure 5 illustrates the encrypted pivot pixel and interpolated pixel in accordance
with an embodiment of the present disclosure;


DESCRIPTION
For the purpose of promoting an understanding of the principles of the invention, reference
will now be made to the embodiment illustrated in the drawings and specific language will be used
to describe the same. It will nevertheless be understood that no limitation of the scope of the invention
is thereby intended, such alterations and further modifications in the illustrated system, and such
further applications of the principles of the invention as illustrated therein being contemplated as
would normally occur to one skilled in the art to which the invention relates.
It will be understood by those skilled in the art that the foregoing general description and the
following detailed description are exemplary and explanatory of the invention and are not intended
to be restrictive thereof.




CLAIM
We Claim
I. A system for reversible data hiding in encrypted images, the system comprises of:
a transmitter end;
a receiver end;
wherein the transmitter end comprises of:
a collection module for collecting an input image data, wherein the input image data undergoes a
pre-processing for enhancing a plurality of pixels of the input image data;
an encryption module connected to the collection module for encrypting the pixels of the collected
image using a benchmark encryption technique, wherein the encrypted image under goes an
interpolation of columns using an interpolation technique;
a data embedding module connected to the encryption module for receiving an encrypted image
and embedding a message in the encrypted pixels, whereinthe encrypted pixels are paired and
.each pair is assigned a symbol for storing at least a message;
wherein the receiver end comprises of:
an extraction module connected to the data embedding module for receiving a marked message
and extracting an original message from the embedded marked message, wherein the interpolated
columns and rows of the pixels are discarded; and
a decryption module connected to the extraction module for decrypting the encrypted image and
obtaining the original image at a receiver end.
2. The system as claimed in claim I, wherein the size of the embedded image doubles with respect
to the column, whereas number of rows remains the same as of the collected image.
3. The system as claimed in claim I, wherein the symbol comprises of binary values and the symbol
assigned during embedding is recorded in a neighboring interpolated pixel, wherein all the
interpolated pixels in alternate columns of each row is formatted.
4. The system as claimed I, wherein embedding is performed in an encrypted pivot pixel, wherein
at least eight message biis are embedded in each encrypted pivot pixels.
5. The system as claimed in claim I, wherein the embedding technique comprises steps of:
When the bit is '0' the bit is considered as even bit and the bit positions in the encrypted pivot
pixel 6,4,2,0 is considered as even positions; and
when the bit is' I' tlie bit is considered as odd bit and the bit positions in 7,5,3, 1 is considered as
odd positions.

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