TripleS

A Project Report on Triple -S a secret Sharing and Storing Application Submitted in partial fulfillment of the requirement for the award of the degree of

BACHELOR OF TECHNOLOGY IN COMPUTER SCIENCE & ENGINEERING BY SANGEM BALAKRISHNA Roll No: B091457 SATHISH GADHAM Roll No: B091473 Under the Supervision of Mr. SUJOY SARKAR

Department of Computer Science and Engineering Rajiv Gandhi University of Knowledge Technologies Basar-504107 2014-2015

CERTIFICATE This is to certify that the Project report entitled “Triple-S a secret sharing and storing application” is a Bona fide work done by following students:

1. Sangem Balakrishna

:

B091457

2. Gadham Sathish

:

B091473

Submitted in the partial fulfillment of the requirement for the award of the degree of Bachelor of Technology in Computer Science and Engineering during the Academic year 2014-15

__________________ Mr. SUJOY SARKAR

__________________

Supervisor,

External Examiner

Department of CSE, RGUKT Basar.

__________________________

Head of the Department Department of CSE, RGUKT Basar.

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DECLARATION

We hereby declare that the work embodied in this report has been carried out by us under the supervision of Mr.Sujoy Sarkar in the Department of Computer Science and Engineering, Rajiv Gandhi University of Knowledge Technologies, Basar and has not been submitted to any other University. Information derived from the published and unpublished work of others has been acknowledged and a list of reference is given.

_____________________ Mr.Sangem Balakrishna ID.No B091457 _________________ Mr.Sathish Gadham ID.No B091473 Place: Date:

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ACKNOWLEDGEMENT

We the Final year project team members of Project “Triple S” are overwhelmed in all humbleness and gratefulness to acknowledge our depth to all those who have helped us to put our ideas and assigned work, well above the level of simplicity and into something concrete. We would like to extend our special thanks of gratitude to Mr. Sujoy Sarkar for providing us an opportunity to work under one of his esteemed projects by being our Project Guide, constantly motivating for doing better and showing confidence in our work. With the help of his suggestions, guidance and encouragement, we all were able to complete our tasks properly and with satisfaction. With immense pleasure, we thank Mr. N ChandraShekar, Head of the Department of Computer Science and Engineering, for the encouragement extended by his timely help throughout the project schedule and the course of study. Finally we would thank our parents, our friends for putting up with our constant moaning about the project and constantly supporting us through the difficult times and critical junctures!

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TABLE OF CONTENTS Abstract……………………………………………………………………………………………………………………….7 Chapter 1 Introduction…………………………………………………………………………………………………………………8 1.1 Need and Motivation………………………………………………………………………………………..8 1.2 Overview of work done…………………………………………………………………………………….9 1.3 Organization of this report…………………………………………………………….…..………… 10 Chapter 2 Background and Related Works…………………………………………………………………………………11 2.1 Existing Solutions ………………………………………………………………………………………… 11 2.2 Algorithms …………………………………………………………………………………………………….11 RSA public key algorithm……………………………………………………………………………...12 Shamir Secret Sharing Scheme……………………………………………………………………..12 Chapter 3 Design ……………………………………………………………………………………………………………………….13 3.1 Scope and Functional Requirements……………………………………………………………….13 3.2.Project Requirement Specification………………………………………………………………….13 3.3 Project Design Specification………….………………………………………………………………..14 3.3.1 Encryption of file…………………..……………………………………………………………….14 3.3.2 Decryption of file……………………………………………………………………………………14 5

3.3.3 File sharing ……..…………………………………………………………………………………….14 3.3.3. Secret communication………………………………………………………………………….14 3.4 Architectural View …………………………………………………………………………………………15 3.4.1 Use case diagram…………………………………………………………………………………..15 Chapter4 Implementation……………………………………………………………………………………………………………….16 4.1 Technologies ………………………………………………………………………………………………….16 4.2 Demonstration (Screen shots)………………………………………………………………………..17 Chapter 5 Conclusion and Future Work……………………………………………………………………………………………24 Chapter 6 Bibliography ………………………………………………………………………………………………………………...…25

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Abstract The main aim of this project is to develop an application which is used to share data and providing security for that data by using RSA(Ronald Rivest, Adi shamir and Loenard adleman) combining with shamir-secret sharing scheme. We want to give new aspect to “Data storing”, for example existence of single key, secret communication while sharing etc. Cryptography and security: the study of techniques and Applications for secure communication as well as secure storing. RSA: RSA is public key cryptographic system (asymmetric) which is used to protect the data by using encryption and decryption process. Encryption process is done by public key and decryption process is done by private key. Where a private key is kept secret. Shamir Secret Sharing Scheme: A secret is divided into shares and the secret again will Be reconstructed using those shares. In this scheme the secret key is shared among a group of people and the shared secret is reconstructed if and only if the minimum number of users or clients participated in reconstruction process. We have developed an Application named “TripleS” with 4 Modules ,which is used for encrypting a file and sending key in the form of shares, and the Key again will be reconstructed using those shares and the decryption of file will be done. To do this successfully, there should be Secret communication, Secret file sharing among the share holders , So we have Developed Secret Communication and Secret file sharing module.

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1. Introduction

1.1 Need and Motivation What is Cryptography and need of Cryptography? The study of techniques and applications that depend on the existence of difficult problems. To most people, cryptography is concerned with keeping communications private. Indeed, the protection of sensitive communications has been the emphasis of cryptography throughout much of its history. There are two types of cryptosystems: secret-key and public-key cryptography. In secret-key cryptography, also referred to as symmetric cryptography, the same key is used for both encryption and decryption. In public-key cryptography, each user has a public key and a private key. The public key is made public while the private key remains secret. Encryption is performed with the public key while decryption is done with the private key. Encryption is the transformation of data into a form that is as close to impossible as possible to read without the appropriate knowledge. Its purpose is to ensure privacy by keeping information hidden from anyone for whom it is not intended, even those who have access to the encrypted data. Decryption is the reverse of encryption; it is the transformation of encrypted data back into an intelligible form.

What is RSA? The RSA public-key cryptosystem is the most popular form of public-key cryptography. RSA stands for Rivest, Shamir, and Adleman, the inventors of the RSA cryptosystem. The first letter in each of its inventors’ last names. The RSA cryptosystem offers both encryption and digital signatures. It is currently difficult to obtain the private key d from the public key (n; e). However if one could factor n into p and q, then one could obtain the private key d. Thus the security of the RSA system is based on the assumption that factoring is difficult. The discovery of an easy method of factoring would ‘‘break’’ RSA. An ‘‘RSA operation,’’ whether encrypting, decrypting, signing, or verifying is essentially a modular exponentiation. This computation is performed by a series of modular multiplications.

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What is Shamir Secret Sharing? Shamir-secret sharing scheme in which the secret key is shared among a group of people and the shared secret is reconstructed by threshold (minimum number of people needed to decrypt the key) group of people. Consider a company that needs to use RSA to apply a digital signature with its private key to a document that will be sent outside the company. An easy way to allow various executives to apply the signature is for each executive to have a copy of the private key, meeting the requirements of efficiency and availability, yet this system is not safe and is corrupted by compromise of a single executive's machine. The opposing approach of requiring the cooperation of all executives in order to sign a check is secure, but is inefficient and lacks availability. So there is need for overcome this problem and Shamir secret sharing scheme is used.

1.2 Over view of work done We have developed an application which is used to share the security information among a group of people. Here we used the idea of RSA algorithm which is used to encrypt the data by using public key and decrypt the data using private key. A file will be encrypted and shares of the key which is generated by RSA will be generated. Decryption process and is done on the basis of Shamir secret sharing scheme in which to decrypt the key a minimum number of clients needs to be participated and the decryption is done. And file can be shared among group of people, while data is transferred in cipher and decrypted at the receiving end. To do the above process we developed four modules which are Encryption module, Decryption module, Secret sharing module and Secret communication module.

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1.3 Organization of this report This report contains exactly 6 chapters giving the details of our project.Chapter1 which is all about the introduction presents the need and motivation behind our project and a simple overview of work that we have done in fulfilling the project. Chapter 2 which deals with the background and related works gives the details about the project and study of Existing solutions. Chapter 3 deals about the design of the application giving the complete description of the Scope and Functional requirements of the project and an overview of the modules present in the project the algorithms used in this project are explained. Chapter 4 is the one which gives the complete implementation details that includes the technologies we have used followed by the high level implementation details describing the each and every detail of modules present, their functionalities and implementation process. It is followed by the screenshots describing the demonstrations of the application and testing of the application. Chapter 5 deals with the conclusion part which also includes the future work of the application to be done. The report ends with Chapter 6, bibliography which have a list of all the references we have gone through during our project.

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2. Background and Related works Threshold decryption has been studied a lot for the last two decades. It is a branch of public key cryptography in general, and multi-party computation in particular. Essentially, in a k-out-of-n threshold crypto-system, denoted (k, n) where 1 < k