International Journal of Computer Applications (0975 – 8887) Volume 168 – No.1, June 2017 24 Hybrid Encryption based SHA2-256 Integration Techniques for High Security for Data Stored in Cloud Environment Keerti Verma Dept.Computer Science and Engineering OIST, Bhopal Sreeja Nair Dept.Computer Science and Engineering OIST, Bhopal ABSTRACT Cloud Computing is the pool of shared resources provided to the user by the Cloud service providers. Many software or application programs are made available to the user at low cost and the deployment environment also provided by the third party cloud providers which are having a full control over the application settings. Since user has no control on the settings of application programs there is always be trust and security issues. The data on the remote cloud server is not secure as a large amount of data is moving to and fro between large number of authorized and unauthorized users. The data can be easily modified by the intruders in the public deployment environment. Thus the using of security algorithms like makes it easier for the security of data to user. General Terms AES Encryption ,obfuscation ,Secure Hash Algorithm Keywords Cloud Computing, Data Security,integrity. 1. INTRODUCTION For maintaining the data and software applications on the central remote servers there is use a technology called Cloud Computing. It allows the user to access their data which are saved on central remote servers using internet. It is and architecture of shared pool computing resource provided to the user to store their data which can be rapidly released with less managerial effort or clod provider interaction. Users have full access on featured applications provided by the cloud on rent. They can built application programs, deploy software and various applications at low cost. The data storage is the main feature which is provided by the cloud to the user with the use on internet and to computing infrastructure like network accessible data storage. Cloud Computing is basically an Information Technology Services provided to the User through Internet. Some of the leading large companies which are providing cloud computing services to the user are Google, Yahoo, Amazon and YouTube [1]. Cloud Computing uses the concept of virtualization that means hiding the detailed information and only showing the useful application information or providing only the network deployment environment. These deployment models of Cloud Computing are divided into three parts they are as follows Public, Private and Hybrid. In the Public deployment environment, the services provided to the user by cloud are having full control of service provider and user can only use services on rent so the data stored on public cloud are less secure as there exists a large number of users’ data which can be accidently or intentionally changed or lost. Private Deployment environment are the cloud services owned by the organization and the data in private cloud are more secure than public cloud as the data can move to and fro in public cloud in the network. Hybrid Cloud possess more than one deployment environment [2][3]. 2. SERVICE MODELS OF CLOUD There are three services models provided by the Cloud Computing Technology and they are as follows: Platform as a Service (PaaS), Software as a Service (SaaS) and Infrastructure as a Service (IaaS) [4][5][6]. 2.1 PaaS model The platform to deploy the application programs or software are provided to the user by the cloud. Only the application program settings controls are given to the user and the physical settings are restricted by the service provider. 2.2 SaaS model The software services are provided by the service provider to the end users only the application can be install and run by the user but cannot be changed as the infrastructure and physical setting controls are under service provider. 2.3 IaaS model The blueprint or the infrastructure is provided to the user on which the application or software programs can be built and deployed. In this model the online data storage, servers and networking components are all provided by the cloud service provider. 3. SECURITY ISSUES As the Cloud Computing is the fast growing technology, it has many new challenges with it. The main feature of cloud computing is its data storage service which has brought many small enterprises to a leading growth. There are lots of security issues in cloud data storage service which has to be look after and curbed [7]. Trust is the main issue as the user is not sure of the service provided by the cloud service provider is ethical or not. As the data can be modified or not secured by the intruders. There is a agreement between the user and the cloud service provider which is known a s Service Level Agreement (SLA) document. There is no standard maintained for the SLA that is why the trust issue is there in cloud environment. Confidentiality [8] [9] of the data is again another security issue in Cloud computing as the important and sensitive data which need to be prevent from disclose. It is a big issue for which so many methods are used to protect confidential information like encryption and cryptography technique. These methods are really expensive and time consuming but to keep the data safe in cloud storage there is a need of them.