Novel Approach for Color Extended Visual
Cryptography Using Error Diffusion
Abstract:
Cloud storage enables users to remotely store their data and enjoy the ondemand high quality cloud applications without the burden of local hardware and
software management. Though the benefits are clear, such a service is also
relinquishing users’ physical possession of their outsourced data, which inevitably
poses new security risks towards the correctness of the data in cloud. In order to
address this new problem and further achieve a secure and dependable cloud
storage service, we propose in this paper a flexible distributed storage integrity
auditing mechanism, utilizing the homomorphism token and distributed erasurecoded data. The proposed design allows users to audit the cloud storage with very
lightweight communication and computation cost. The auditing result not only
ensures strong cloud storage correctness guarantee, but also simultaneously
achieves fast data error localization, i.e., the identification of misbehaving server.
Considering the cloud data are dynamic in nature, the proposed design further
supports secure and efficient dynamic operations on outsourced data, including
block modification, deletion, and append. Analysis shows the proposed scheme is
highly efficient and resilient against Byzantine failure, malicious data modification
attack, and even server colluding attacks.
Architecture:
Existing System:
Visual cryptography is the art and science of encrypting the image in such a way
that no-one apart from the sender and intended recipient even realizes the original
image, a form of security through obscurity. By contrast, cryptography obscures
the original image, but it does not conceal the fact that it is not the actual image.
Limitation:-The existing system does not provide a friendly environment to
encrypt or decrypt the data.
Disadvantages:
1. The contrast of the reconstructed image is not maintained.
2. Perfect alignment of the transparencies is troublesome.
3. Additional processing is required for colored images.
Proposed System:
Proposed system Visual cryptography provides a friendly environment to
deal with images. Generally cryptography tools supports only one kind of image
formats. Unlike standard EVCS, the robustness of our proposed scheme to cheating
comes from that fact that it is impossible to differentiate VIPs and other pixels in
the encrypted shares and it is hard to know the actual VIP values which were
decided during the error diffusion. Based upon the principle of VC, extended VC
has been proposed whose shares take meaningful images rather than random noiselike patterns to avoid suspicion.
Advantages:
1. Simple to implement,
2. Decryption algorithm not required (Use a human visual system). So a
person unknown to cryptography can decrypt the message.
3. We can send cipher text through Fax or E-Mail.
4. Lower computational cost since the secret message is recognized only by
human eyes and not cryptographically computed.
Modules:
1. Visual Cryptography
1. Visual Cryptography
Sharing a secret color image and also to generate the meaningful share to transmit
secret color image Chang and Tsai anticipated color visual cryptography scheme.
For a secret color image two significant color images are selected as cover images
Which is the same size as the secret color image? Then according to a predefined
Color Index Table, the secret color image will be hidden into two camouflage
images. One disadvantage of this scheme is that extra space is required to
accumulate the Color Index Table. In this scheme also number of subpixels is in
proportional to the number of colors in the secret image as in Verheul and Van
Tilborg Yang and Laih schemes. When more colors are there in the secret image
the larger the size of shares will become. To overcome this limitation Chin-Chen
Chang et al developed a secret color image sharing scheme based on modified
visual cryptography. This scheme provides a more efficient way to hide a gray
image in different shares. In this scheme size of the shares is fixed; it does not vary
when the number of colors appearing in the secret image differs. Scheme does not
require any predefined Color Index Table. Though pixel expansion is a fixed in
this scheme is not suitable for true color secret image.
System Requirements:
Hardware Requirements:
• System
: Pentium IV 2.4 GHz.
• Hard Disk
: 40 GB.
• Floppy Drive
: 1.44 Mb.
• Monitor
: 15 VGA Colour.
• Mouse
: Logitech.
• Ram
: 512 Mb.
Software Requirements:
• Operating system
: Windows 7 Ultimate(32-bit).
• Coding Language
: ASP.Net with C#
• Data Base
: SQL Server 2008,VS2010