International Journal of Computer, Information Technology & Bioinformatics (IJCITB)ISSN: 2278-7593, Volume-2, Issue-3, 2014 www.ijcitb.com 17 Dataset Segmentation for Cloud Data Storage and Securing Data Using Cryptography Vidyanand Ukey, Nitin Mishra Information Technology Department, RGPV University vidyanandukey@gmail.com nitin.nriist@gmail.com Abstract - Cloud Computing is a new computing model that distributes the computing missions on a resource pool that includes a large amount of computing resources. More and more companies begin to provide different kinds of cloud computing services for Internet users at the same time these services also bring some security problems. Internet users are able to acquire computing resource, storage space and other kinds of software services according to their needs. In cloud computing, with a large amount of various computing resources, users can easily solve their problems with the resources provided by a cloud. Today most cloud computing system use cryptography techniques to provide data security and mutual authentication. This research paper helps in securing the data without affecting the original data and protecting the data. In this technique the data are segmented into three different levels according to their data importance ranking, set by data owner. The vital data in each level can be encrypted by using encryption/decryption algorithm and keys before store them in the Cloud. In this technique the aim is to store data in a secure and safe way in order to avoid intrusions and attacks. Also, it will reduce the cost and time to store the encrypted data in the Cloud Computing. The paper conducts a performance analysis by implementing the Advanced Encryption Standard (AES) in all levels in order to check the performance of model. Keywords - Advanced Encryption Standard (AES), Cloud Computing, Segmentation, Security. I. INTRODUCTION Cloud Computing is a new computing model that distributes the computing missions on a resource pool that includes a large amount of computing resources. It is the result of development of infrastructure as a service (IAAS), platform as a service (PAAS), and software as a service (SAAS). With broadband Internet access, Internet users are able to acquire computing resource, storage space and other kinds of software services according to their needs. In cloud computing, with a large amount of various computing resources, users can easily solve their problems with the resources provided by a cloud. This brings great flexibility for the users. Using cloud computing service, users can store their critical data in servers and can access their data anywhere they can with the Internet and do not need to worry about system breakdown or disk faults, etc. Also, different users in one system can share their information and work, as well as play games together. Many important companies such as Amazon, Google, IBM, Microsoft, and Yahoo are the forerunners that provide cloud computing services. Recently more and more companies such as Salesforce, Facebook, Youtube, Myspace etc. also begin to provide all kinds of cloud computing services for Internet users. There are mainly three types of clouds: private clouds, public clouds and hybrid clouds [15]. Private clouds, also called internal clouds, are the private networks that offer cloud computing services for a very restrictive set of users within internal network. For example, some companies and universities can use their internal networks to provide cloud computing services for their own users. These kinds of networks can be thought as private clouds. Public clouds or external clouds refer to clouds in the traditional sense [13], such as enterprises that provide cloud computing services for the public users. Hybrid clouds are the clouds that include multiple private and/or public clouds [14]. Providing security in a private cloud and a public cloud is easier, comparing with a hybrid cloud since commonly a private cloud or a public cloud only has one service provider in the cloud. Providing security in a hybrid cloud that consisting multiple service providers is much more difficult especially for key distribution and mutual authentication. Also for users to access the services in a cloud, a user digital identity is needed for the servers of the cloud to manage the access control. While in the whole cloud, there are many different kinds of clouds and each of them has its own identity management system. Thus user who wants to access services from different clouds needs multiple digital identities from different clouds, which will bring inconvenience for users. Using federated identity management, each user will have his unique digital identity and with this identity, he can access different services from different clouds. Identity-based cryptography [10] is a public key technology that allows the use of a public identifier of a user as the user’s public key. Hierarchy identity-based cryptography is the development from it in order to solve the scalability problem. Recently identity-based cryptography and hierarchy identity-based cryptography have been proposed to provide security for some Internet applications [11] [8] [12] and [5]. Cloud computing allows user to store large amount of data in cloud storage and use as and when required, from any part of the world, via any terminal equipment. Since cloud computing is rest on internet, security issues like privacy, data security, confidentiality, and authentication is encountered. In