International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395 -0056 Volume: 04 Issue: 05 | May -2017 www.irjet.net p-ISSN: 2395-0072 © 2017, IRJET | Impact Factor value: 5.181 | ISO 9001:2008 Certified Journal | Page 711 Data Encryption and File Sharing 1 Rafi Uz Zaman, 2 Parth Utkarsh, 3 Luv Tanwani, 4 Atul Kumar 123 Computer Science & Engineering, IMS Engineering College, Ghaziabad, 201009, India ___________________________________________________________________________________________________________________________________________________ Abstract- This paper is proposing a web based application that would provide a framework to the user to encrypt his data using a symmetric key cryptographic algorithm on the client’s local machine itself. This would enable the user to be assured that the confidentiality of the user’s data is maintained even from the encryption service providers themselves. Keywords- Symmetric key encryption/decryption, application architecture, files upload and sharing. Introduction- With the ever increasing digitalization the risk of data leaks over the internet have increased exponentially. This calls an immediate need for preventative measures against confidentiality breaches. Encryption of data has been looked upon as a promising technique over the previous few decades. The motivation for the development of this application came when a very well known cloud service provider was hacked in the late 2016 which resulted in the leak of sensitive information of the users. Moreover many big reputed giants were accused of sharing the sensitive user data with the several government agencies voluntarily. Keeping all this in mind we have created a web application based on a client- server architecture that provides encryption decryption services to the users without implementing any backdoors. The whole application architecture ensures complete confidentiality of the data provided by the client even from the server itself. Apart from encryption and decryption, if a user wishes to upload an encrypted file on the server so that they might download it later from any remote machine, he/she can easily do so by using the upload functionality of the application. Only encrypted files are allowed to be uploaded on the server and links to the uploaded files are automatically generated and returned to the user. All the users are allotted some space on the drive where the data is securely stored in separate partitions for each user. Literature Review Many papers were studied during the development of this application out of which the main ones were considered and used as a base for this comparison report. Tiny Encryption Algorithm that was developed by David Wheeler and Roger Needham has been used in this application. Few of the papers which were considered are as mentioned- [1] Wheeler, David J. And Needham, Roger M. TEA, a Tiny Encryption Algorithm Computer Laboratory, Cambridge University, England, November 1994. [2] Wheeler, David J And Needham, Roger M TEA Extensions. Computer Laboratory, Cambridge University, England. October 1997. [3] Steil, Michael. 17 Mistakes Microsoft Made in the Xbox Security System. October, 2005. These papers were referred to analyse the running time complexity, implementation complexity and the strength of the above proposed algorithm. Methodology- This project involves providing cryptographic security to user data. Based on functionality the project can be divided into four major modules: