This document proposes a method for separable reversible data hiding in encrypted images. The method uses different keys for image encryption and data hiding, allowing the data and original image to be retrieved independently. This improves on existing systems that use the same key for encryption and data hiding, allowing anyone with the key to access both the hidden data and original image. The proposed method encrypts images with an encryption key, then hides data in the encrypted images with a separate data hiding key. Receivers with the data hiding key can retrieve the hidden data, and receivers with the encryption key can retrieve the original image, without extracting the hidden data.

1. SEPARABLE REVERSIBLE DATA HIDING IN ENCRYPTED IMAGE
OBJECTIVE:
The objective of this project is to provide an efficient data hiding
technique and image Encryption in which the data and the image can be
retrieved independently.
PROBLEM DIFINITION:
The problem found in our existing system as, the secret key used for
encryption of compressed image and the data hiding is same. So, the user who
knows the secret key used for encryption can access the data embedded and the
original data. The original Image can be retrieved from the encrypted image
after extracting or removing the data hidden in the image. The content owner
and the data hider share the same encryption key for the encryption of the Image
and data hiding.
ABSTRACT:
The use of computer networks for data transmissions has created
the need of security. Many robust message encryption techniques have been
developed to supply this demand. The amount of digital images has increased
rapidly on the Internet. Image security becomes increasingly important for
many applications, e.g., confidential transmission, video surveillance, military
and medical applications. Nowadays, the transmission of images is a daily

2. routine and it is necessary to find an efficient way to transmit them over
networks.
To decrease the transmission time, the data compression is necessary. The
protection of this multimedia data can be done with encryption or data hiding
algorithms. Since few years, a problem is to try to combine compression,
encryption and data hiding in a single step. For example, some solutions was
proposed in3 to combine image encryption and compression. Two main groups
of technologies have been developed for this purpose.
The first one is based on content protection through encryption. There are
several methods to encrypt binary images or gray level images. In this group
proper decryption of data requires a key. The second group bases the protection
on digital watermarking or data hiding, aimed at secretly embedding a message
into the data. Encryption and watermarking algorithms rely on the Kirchhoff’s
principle: all the details of the algorithm are known, and only the key to encrypt
and decrypt the data should be secret.
EXISTING SYSTEM:
In the existing system reversible data hiding technique the
image is compressed and encrypted by using the encryption key and the data to
hide is embedded in to the image by using the same encryption key. The user
who knows the secret encryption key used can access the image and decrypt it
after extracting or removing the data hidden in the image. After extracting the
data hidden in the image then only can be the original image is retrieved.

3. DISADVANTAGES:
 The secret key used for encryption of compressed image and the data
hiding is same. So, the user who knows the secret key used for encryption
can access the data embedded and the original data.
 The original Image can be retrieved from the encrypted image after
extracting or removing the data hidden in the image.
 The content owner and the data hider share the same encryption key for
the encryption of the Image and data hiding.
PROPOSED SYSTEM:
In proposed method the image is encrypted by content
owner by using the encryption key. The data hider can hide the data in the
encrypted image compressing the least significant bits of the encrypted image to
obtain the space to hide the data by using data hiding key. At the receiver side
the data can be retrieved using the data hiding key by decrypting the image. But,
the encrypted image unchanged still it is decrypted using the encryption key.
The receiver who has the both the encryption and data hiding keys can access
the data embedded as well as the original image.
ADVANTAGES:
 The data hiding and image encryption are done by using two different
keys. That is encryption key and the data hiding key.
 The receiver who has the data hiding key can retrieve the data
embedded.

4.  The receiver who has the encryption key can retrieve the original
image without removing or extracting the data embedded in the
encrypted image.
 The receiver who has the both the keys can retrieve the data hidden
and the original image from the encrypted image.
ALGORITHM USED:
1. LSB (Least Significant Bit)
2. DES (Data Encryption Standard)
ARCHITECTURE DIAGRAM:

5. SYSTEM REQUIREMENTS:
Hardware Requirements:
 Intel Pentium IV
 256/512 MB RAM
 1 GB Free disk space or greater
 1 GB on Boot Drive
 1 Network Interface Card (NIC)
 GSM
Software Requirements:
 MS Windows XP/2000
 MS IE Browser 6.0/later
 MS .Net Framework 2.0
 MS Visual Studio.Net 2005
 Internet Information Server (IIS)
 MS SQL Server 2000
 Windows Installer 3.1
APPLICATIONS:
1. Deductive Agencies
2. Consultancies
3. Bank Information Sharing’s