Seminar Report On VISUAL CRYPTOGRAPHY

Today, the world is on the anvil of being shrunk into a global net. All the systems around the world are to be used in the epoch of a nanosecond even when installed across continents and oceans. This is possible only through networks. It is in this context that networks become crucial to the viability of science and engineering research. The unprecedented growth of networking has helped in breaking all geographic barriers of the world and building the information super highway and global village.

In this direction a new technology has developed in the past few years which makes it possible to interconnect many disparate networks and make them work as a co-coordinated unit. Thus the technology is designed to foster the communication between 2 machines with hardware architectures, to accommodate and use any packet switched network hardware and to accommodate multiple operating systems.

It is in this context that Visual Cryptography has gained importance for communications between disparate networks.

2.   SYSTEM ANALYSIS

System Analysis is first stage according to System Development Life Cycle model. This System Analysis is a process that starts with the analyst.

          Analysis is a detailed study of the various operations performed by a system and their relationships within and outside the system.  One aspect of analysis is defining the boundaries of the system and determining whether or not a candidate should consider other related systems.  During analysis, data is collected from the available files, decision points, and transactions handled by the present system.

          Logical system models and tools are used in analysis.  Training, experience, and common sense are required for collection of the information needed to do the analysis.

3.1 Existing System

The present system is having different networks for each department. Where in the files has to be manually transferred. which is not a good way of practice of file transfer, for that we have given this proposed system. Where the file transfer is done through the networks.

3.2 Problem Statement

                             A computer network is a communication system for connecting end system,  in order to send messages or files. From one to another. So to achieve proper communication the network should be a dedicated one. the interconnection i.e. physical connections should be proper.

 Whenever a new network is added it should not disturb the existing network. Similarly when a network is deleted communication should be carried on properly

The network should be reachable with a high reliability and should provide consistent routing and should be able to provide solution for the routing problem.

3.3 Proposed System

          Visual cryptography (VC) is a method of encrypting a secret image into shares such that stacking a sufficient number of shares reveals the secret image. Shares are usually presented in transparencies. Each participant holds a transparency. Most of the previous research work on VC focuses on improving two parameters: pixel expansion and contrast. In this paper, we studied the cheating problem in VC and extended VC. We considered the attacks of malicious adversaries who may deviate from the scheme in any way. We presented three cheating methods and applied them on attacking existent VC or extended VC schemes. We improved one cheat-preventing scheme. We proposed a generic method that converts a VCS to another VCS that has the property of cheating prevention. The overhead of the conversion is near optimal in both contrast degression and pixel expansion.

3.4 REQURIEMENTS ANALYSIS

The requirement phase basically consists of three activities:

1.           Requirement Analysis

2.           Requirement Specification

3.           Requirement Validation

Requirement Analysis:

          Requirement Analysis is a software engineering task that bridges the gap between system level software allocation and software design. It provides the system engineer to specify software function and performance, indicate software’s interface with the other system elements and establish constraints that software must meet.

          The basic aim of this stage is to obtain a clear picture of the needs and requirements of the end-user and also the organization. Analysis involves interaction between the clients and the analysis. Usually analysts research a problem from any questions asked and reading existing documents. The analysts have to uncover the real needs of the user even if they don’t know them clearly. During analysis it is essential that a complete and consistent set of specifications emerge for the system. Here it is essential to resolve the contradictions that could emerge from information got from various parties.

This is essential to ensure that the final specifications are consistent.

It may be divided into 5 areas of effort.

1.           Problem recognition

2.           Evaluation and synthesis

3.           Modeling

4.           Specification

5.           Review

Each Requirement analysis method has a unique point of view. However all analysis methods are related by a set

of operational principles. They are

·                     The information domain of the problem must be represented and understood.

·                     The functions that the software is to perform must be defined.

·                     The behavior of the software as a consequence of external events must be defined.

·                     The models that depict information function and behavior must be partitioned in a hierarchical or layered fashion.

·                     The analysis process must move from essential information to implementation detail.

3.5 REQUIREMENTS SPECIFICATION

Specification Principles:

          Software Requirements Specification plays an important role in creating quality software solutions. Specification is basically a representation process. Requirements are represented in a manner that ultimately leads to successful software implementation.

Requirements may be specified in a variety of ways.  However there are some guidelines worth following: -

·                     Representation format and content should be relevant to the problem

·                     Information contained within the specification should be nested

·                     Diagrams and other notational forms should be restricted in number and consistent in use.

·                     Representations should be revisable.

Software Requirements Specifications:

          The software requirements specification is produced at the culmination of the analysis task.  The function and performance allocated to the software as a part of system engineering are refined by establishing a complete information description, a detailed functional and behavioral description, and indication of performance requirements and design constraints, appropriate validation criteria and other data pertinent to requirements.

Introduction

Even with the remarkable advance of computer technology, using a computer to decrypt secrets is infeasible in some situations. For example, a security guard checks the badge of an employee or a secret agent recovers an urgent secret at some place where no electronic devices are applied. In these situations the human visual system is one of the most convenient and reliable tools to do checking and secret recovery. Visual cryptography (VC), proposed by Naor and Shamir [1], is a method for protecting image-based secrets that has a computation-free decryption process. In the (2, 2) VC scheme each secret image is divided into two shares such that no information can be reconstructed from any single share. Each share is printed in transparencies. The decryption process is performed by stacking the two shares and the secret image can be visualized by naked eye without any complex cryptographic computations. In the above basic VC scheme each pixel ‘p’ of the secret image is encrypted into a pair of sub pixels in each of the two shares. If ‘p’ is white, one of the two columns under the white pixel in Fig. 1 is selected. If p is black, one of the two columns under the black pixel is selected. In each case, the selection is performed randomly such that each column has 50% probability to be chosen. Then, the first two pairs of sub pixels in the selected column are assigned to share 1 and share 2, respectively. Since, in each share, p is encrypted into a black–white or white–black

1.1        Product Function

             This project is divided into four modules:

 

      Module 1:

                   In this module we provide mechanisms for adding a new network to a Visual Cryptography and deleting the existing network from the Visual Cryptography and displaying a routing table for a Visual Cryptography.

     Module 2:

                   In this module there are three methods first, to create a route message, second sending a routing message to other Visual Cryptographys, third updating the routing message.

       Module 3:

                 In this module we develop an application program to know the date and time the routing table is transferred to other Visual Cryptography.

         Module 4:

                In this module the errors occurred by the invalid inputs given by the user or any unexpected circumstances is reported to the Visual Cryptography by using ICMP protocol.

 Operating Environment

      

Software Requirements:

Operating system: windows 98/2000/NT

          Language: Java

Protocols: TCP/IP, HTTP

             Hardware Requirements:

            Processor: Pentium III

            RAM: 128MB

                   Hard Disk: 2GB

1.2        Design and Implementation constraints

          

          This protocol is implemented in Java language .We also use HTTP/TCP/IP protocols.

             Java has had a profound effect on the Internet. The reason for this is Java expands the universe of objects that can be about freely on the Internet. There are two types of objects we transmit over the network, passive and dynamic.

  

  Network programs also present serious problems in the areas of security and portability. When we download a normal program we risk viral infection. Java provides a firewall to overcome these problems. Java concerns about these problems by applets. By using a Java compatible Web browser we can download Java applets without fear of viral infection.

             

1.3        Assumptions and Dependencies

   We assume that there are several servers and clients attached to it.

               User system supports TCP/IP protocols.

 The key considerations of Java are

1.   Object Oriented: Java purist’s “everything is an object” paradigm. The java object model is simple and easy to extend.

2.   Multithreaded: Java supports multithreaded programming which allows you to write programs that do many things simultaneously.

3.   Architecture-Neutral: the main problem facing programmers is that no guarantee that if you write a program today, it will run tomorrow, even on the same machine. Java language and JVM solves this problem, their goal is to provide “Write once; Run anywhere anytime forever.

4.   Distributed: Java is designed for the distributed environment of the Internet because it handles TCP/IP protocols.

The minimum requirements the client should have to establish a connection to a server are as follows:

     Processor:    Pentium III

     Ram        :  128MB

     Hard Disk:  2 GB

     Web server: Java Web Server

            

      Protocols: TCP/IP

3.External Interface Requirements

 3.1User Interfaces

        This includes GUI standards, error messages for invalid inputs by users, standard buttons and functions that will appear on the screen.

3.2 Hardware Interfaces

         We use TCP/IP protocol for establishing connection          and transmitting data over the network. We use Ethernet for LAN.

3.3 Software Interfaces

 We use Oracle for storing database of clients who connects to the server through JDBC & ODBC.

3.4 Security Requirements

 We provide authentication and authorization by passwords for each level of access.

We implement IDEA algorithm for secure data transmission.

3.5 Software Quality Attributes

    Product is adaptable to any changes.

                    Such as the product can be modified to transfer not only text but also image, audio, video files

          Product is reliable due to the file encryption and authentication.

                   That means the data is not lost or goes into wrong hands.

        Product is portable; it can run between only two connected systems or a large  Network of computers.

                 

          Product is maintainable; i.e. in future the properties of the product can be changed to meet the requirements.                             

3.6 FEASIBILITY STUDY

All projects are feasible, given unlimited resources and infinite time.  But the development of software is plagued by the scarcity of resources and difficult delivery rates.  It is both necessary and prudent to evaluate the feasibility of a project at the earliest possible time.

Three key considerations are involved in the feasibility analysis.

Economic Feasibility:

This procedure is to determine the benefits and savings that are expected from a candidate system and compare them with costs. If benefits outweigh costs, then the decision is made to design and implement the system.  Otherwise, further justification or alterations in proposed system will have to be made if it is to have a chance of being approved.  This is an ongoing effort that improves in accuracy at each phase of the system life cycle.

Technical Feasibility:

Technical feasibility centers on the existing computer system (hardware, software, etc.,) and to what extent it can support the proposed addition. If the budget is a serious constraint, then the project is judged not feasible.

Operational Feasibility:

People are inherently resistant to change, and computers have been known to facilitate change. It is understandable that the introduction of a candidate system requires special effort to educate, sell, and train the staff on new ways of conducting business.

FEASIBILITY STUDY IN THIS PROJECT

Technical Feasibility

Technical feasibility centers on the existing computer system (hardware, software, etc.,) and to

what extent it can support the proposed addition. If the budget is a serious constraint, then the project is judged not feasible.

Economic Feasibility

This procedure is to determine the benefits and savings that are expected from a candidate system and compare them with costs. If benefits outweigh costs, then the decision is made to design and implement the system.  Otherwise, further justification or alterations in proposed system will have to be made if it is to have a chance of being approved.  This is an ongoing effort that improves in accuracy at each phase of the system life cycle.

Operational Feasibility

People are inherently resistant to change, and computers have been known to facilitate change. It is understandable that the introduction of a candidate system requires special effort to educate, sell, and train the staff on new ways of conducting business.

4.       SYSTEM DESIGN

          The most creative and challenging phase of the life cycle is system design.  The term design describes a final system and the process by which it is developed.  It refers to the technical specifications that will be applied in implementations of the candidate system.  The design may be defined as “the process of applying various techniques and principles for the purpose of defining a device, a process or a system with sufficient details to permit its physical realization”.

       The designer’s goal is how the output is to be produced and in what format. Samples of the output and input are also presented.  Second input data and database files have to be designed to meet the requirements of the proposed output.  The processing phases are handled through the program Construction and Testing.  Finally, details related to justification of the system and an estimate of the impact of the

candidate system on the user and the organization are documented and evaluated by management as a step toward implementation.

                   The importance of software design can be stated in a single word “Quality”.  Design provides us with representations of software that can be assessed for quality.  Design is the only way where we can accurately translate a customer’s requirements into a complete software product or system. Without design we risk building an unstable system,  that might fail if small changes are made. It may as well be difficult to test, or could be one who’s quality can’t be tested.  So it is an essential phase in the development of a software product.

9. Conclusion

The main objective of the project, to interconnect different LANs through a Visual Cryptography and to maintain the record of various events and responses of the system is achieved.  This can be used in applications wherein a communication between two or more different networks is required.

Linux provides faster system-to-system communication than other operating systems and the network happens to be highly secured from the administrator’s point of view. The TCP / IP protocol developed in the course of this project is highly reliable and deals with connection oriented systems.

Network security, which is the primary concern of today’s communication world, is successfully implemented using the IDEA algorithm. It provides a safe and secure transmission as it involves multiple manipulations for encryption and so is it with decryption.

The routing algorithm and the TFTP developed are linked with the modules of this project, which finally resulted in the development of a Visual Cryptography-to-Visual Cryptography protocol.