A Lossless Tagged Visual Cryptography
Scheme
Abstract: Visual Cryptography is based on cryptography where n images are encoded
in a way that only the human visual system can decrypt the hidden message
without any cryptographic computations when all shares are stacked together. As
one of the most efficient multi-secret visual cryptography (MVC) schemes. The
tagged visual cryptography (TVC) is capable of hiding tag images into randomly
selected shares. However, the encoding processes of TVC and other MVC schemes
bring distortion to shares, which definitely lowers the visual quality of the decoded
secret image. This letter proposes an extended TVC scheme, named as lossless
TVC (LTVC). Specifically, “lossless” means that the proposed LTVC scheme
encodes the tag image without affecting the rebuilt secret image. A multi-secret
sharing scheme is a protocol to share m arbitrarily related secrets s 1,..., s m among
a set of participants. Pixel expansion and the quality of the reconstructed secret
image has been a major issue of visual secret sharing (VSS) schemes. A number of
probabilistic VSS schemes with minimum pixel expansion have been proposed for
black and white (binary) secret images. This paper presents a probabilistic (2, 3)SS scheme for gray scale images. Its pixel expansion is larger in size but the
quality of the image is perfect when it’s reconstructed. The construction of the
shadow images (transparent shares) is based on the binary OR operation
Existing System: Transmission times for documents encrypted using public key cryptography
are significantly slower then symmetric cryptography. In fact, transmission
of very large documents is prohibitive.
 The key sizes must be significantly larger than symmetric cryptography to
achieve the same level of protection.
 Public key cryptography is susceptible to impersonation attacks
Proposed System: The proposed LTVC scheme encodes the tag image without affecting the
rebuilt secret image
 We propose a tagged VC (TVC) scheme in which more secret images can
be revealed by the folding up operation.
 we propose the probabilistic LTVC (P-LTVC) to solve the potential
security problem of LTVC
 The superiority of the proposed scheme is experimentally verified.
Hardware Requirements:•
SYSTEM
: Pentium IV 2.4 GHz
•
HARD DISK
: 40 GB
•
RAM
: 256 MB
Software Requirements:•
Operating system : Windows XP Professional
•
IDE
: Microsoft Visual Studio .Net 2008
•
Database
: Sql server
•
Coding Language : C#.NET