A Probabilistic Model of (t,n) Visual Cryptography Scheme With Dynamic GroupABSTRACT:The visual cryptography (VC) is a secret sharing scheme where a secret image isencoded into transparencies, and the stacking of any out of transparencies revealsthe secret image. The stacking of or fewer transparencies is unable to extract anyinformation about the secret. We discuss the additions and deletions of users in adynamic user group. To reduce the overhead of generating and distributingtransparencies in user changes, this paper proposes a VC scheme with unlimitedbased on the probabilistic model. The proposed scheme allows to changedynamically in order to include new transparencies without regenerating andredistributing the original transparencies. Specifically, an extended VC schemebased on basis matrices and a probabilistic model is proposed. An equation isderived from the fundamental definitions of the VC scheme, and then the VCscheme achieving maximal contrast can be designed by using the derived equation.The maximal contrasts with to are explicitly solved in this paper.
ARCHITECTURE: SENDER Login Login Details Binary VCS TRANSPARA secret NCIES image SECRET RECEIVER DATAEXISTING SYSTEM:In visual cryptography, the decoding process is performed directly by the humaneyes; while in existing, the shared images need some processing to reconstruct the
secret image. The increasing numbers of possibilities to create, publishes, anddistribute images calls for novel protection methods, new sharing and accesscontrol mechanisms for the information contained in the published images. Secureimage sharing techniques overcome the traditional cryptographic approach,providing new solutions for the development of new and secure imagingapplications.PROPOSED SYSTEM:We have proposed a (t, n) VC scheme with flexible value of (n). From the practicalperspective, the proposed scheme accommodates the dynamic changes of userswithout regenerating and redistributing the transparencies, which reducescomputation and communication resources required in managing the dynamicallychanging user group. From the theoretical perspective, the scheme can beconsidered as the probabilistic model of (t, n) VC with unlimited. Initially, theproposed scheme is based on basis matrices, but the basis matrices with infinitesize cannot be constructed practically. Therefore, the probabilistic model isadopted in the scheme.
MODULES: 1. Login modules. 2. Matrices (Black and White) Method. 3. VC Scheme Method. 4. Encoding Algorithm Method.MODULE DESCRIPTION:Login modules.Login or logon (also called logging in or on and signing in or on) is the process bywhich individual access to a computer system is controlled by identification of theuser using credentials provided by the user.A user can log in to a system tovyfvs and can then log out or log off (perform alogout / logoff) when the access is no longer needed.Logging out may be done explicitly by the user performing some action, such asentering the appropriate command, or clicking a website link labeled as such. It canalso be done implicitly, such as by powering the machine off, closing a webbrowser window, leaving a website, or not refreshing a webpage within a definedperiod.
Matrices (Black and White) Method.The basis matrices of VC scheme were first introduced, a white-and-black secretimage or pixel is also described as a binary image or pixel. In the basis matrices, toencode a binary secret image, each secret pixel white black will be turned intoblocks at the corresponding position of transparencies, respectively. Each blockconsists of subpixels and each subpixel is opaque or transparent. Throughout thispaper, we use 0 to indicate a transparent subpixel and 1 to indicate an opaquesubpixel. If any two subpixels are stacked with matching positions, therepresentation of a stacked pixel may be transparent, when the two correspondingpixels are both transparent.VC Scheme Method.Proposed method is based on the basis matrices and the idea of probabilisticmodel. For a (t, n) VC scheme, the “totally symmetric” form of (B0)and(B1) areboth constructed and described as H0 and H1, respectively.
VC scheme with flexible value of (n). From the practical perspective, the proposedscheme accommodates the dynamic changes of users without regenerating andredistributing the transparencies, which reduces computation and communicationresources required in managing the dynamically changing user group.Encoding Algorithm Method.For a given value of (t), the transparencies can be continuously generated with theOptPrVC scheme. However, practical applications require the algorithm toterminate within finite steps. To meet the requirement, a finite number is used tospecify the number of transparencies in the algorithm.HARDWARE REQUIREMENTS Processor : Any Processor above 500 MHz. Ram : 128Mb. Hard Disk : 10 GB. Compact Disk : 650 Mb.
Input device : Standard Keyboard and Mouse. Output device : VGA and High Resolution MonitorSOFTWARE REQUIREMENTS Operating System : Windows XP. Coding Language : JAVAREFERENCE:Sian-Jheng Lin and Wei-Ho Chung, Member, IEEE, “A Probabilistic Model of(t,n) Visual Cryptography Scheme With Dynamic Group”, IEEETRANSACTIONS ON INFORMATION FORENSICS AND SECURITY,VOL. 7, NO. 1, FEBRUARY 2012.