International Journal of Computer Applications (0975 – 8887) Volume 176 – No.1, October 2017 5 A Secured Homomorphic Encryption Technique in Cloud Computing Nitin Kamble INURTURE, Bangalore Pragati Hiwarkar, PhD INURTURE, Bangalore Monali Bachhav INURTURE, Bangalore ABSTRACT Cloud computing security challenges to many researchers. Priority was to focus on security which is the biggest concern of organizations moving to the cloud. Cloud computing help in costs optimization, easy maintenance and re-provisioning of resources, and so the increased profits. The adoption of Cloud Computing applies only if the security is ensured. How to guaranty a better data security and also how can we keep the client private information confidential? There are two major queries that present a challenge to Cloud computing providers. When the data transferred to the Cloud we use standard encryption methods to secure the operations and the storage of the data. For processing data located on a remote server, the Cloud providers need to access the raw data. In this paper we are proposing a method to execute operations on encrypted data without decrypting them. It will yield the same results after calculations as if we have worked directly on the raw data. Keywords Cloud computing, homomorphic encryption, Ciphertext, Data security 1. INTRODUCTION The rapid abundance of Smartphone technology in urban communities has enabled mobile users to utilize context aware services on their devices. Service providers take benefit of this vibrant and ever-growing technology landscape by proposing innovative context-dependent services for mobile subscribers. Location based Services (LBS), for example, are used by millions of mobile subscribers every day to obtain location-specific information [1]. Cloud computing as a concept is the result of the natural evolution of our everyday approach to using Technology delivered via the Internet. Cloud computing came into the forefront as a result of advances in virtualization (e.g. VMware), distributed computing with server clusters (e.g. Google) and increase in the availability of broadband Internet access. Business leaders illustrate cloud computing simply as the delivery of applications or IT services, which are offered by an intermediary over the Internet (Microsoft, IBM). The recent global economic recession served as a booster for interest in cloud computing technologies as organizations sought for ways to reduce their IT finances, while in harmony with performance and profits. The cloud computing buzz began in 2006 with the Launch of Amazon EC2, gaining footing in 2007. The National Institute of Standards and Technology defines cloud computing as follows: “Cloud computing is a model for facilitating convenient, on demand network access to a common group of configurable computing resources (e.g., networks, servers, storage, applications, and services) can be swiftly provisioned and released with minimal management effort or supplier relations.” Cloud computing is currently characterized by having an on demand access to elastic resources via a lease model. According to reports of CSA (Cloud Security Alliance), the 13 security domains [2] and the 7 top threats [3] on cloud computing were defined as follows; 1) Security domains in cloud computing:  Cloud Computing Architectural Framework  Governance and Enterprise Risk Management  Legal and Electronic Discovery  Compliance and Audit  Information Lifecycle Management  Portability and Interoperability  Traditional Security, Business Continuity, and Disaster Recovery  Data Center Operations  Incident Response, Notification, and Remediation  Application Security  Encryption and Key Management  Identity and Access Management  Virtualization 2) Top threats in cloud computing security:  Abuse and Nefarious Use of Cloud Computing  Insecure Application Programming Interfaces  Malicious Insiders  Shared Technology Vulnerabilities  Data Loss or Leakage  Account, Service & Traffic Hijacking  Unknown Risk Profile "Homomorphic" is an adjective which describes a property of an encryption method. That property, in simple terms, is the capability to perform computations on the cipher text without decrypting it first. The basic concept was to encrypt the data before sending to the Cloud provider. But, this one will have to decrypt each time he has to work on. The client will need to provide the private key to the server to decrypt the data before execute the calculations requisite, which might concern the confidentiality of data stored in the Cloud. The Homomorphic Encryption method is able to perform operations of encrypted data without decrypting them [4]. Homomorphic encryption is the conversion of data into ciphertext that can be analyzed and worked with as if it were still in its unique state. It allows complex mathematical operations to be performed on encrypted data without compromising the encryption. In arithmetic, homomorphic depicts the conversion of one data set into another while preserving relationships. The idiom is resultant of the Greek words "same structure." Since the information in a homomorphic encryption scheme retains the similar structure,