Volume 8, No. 5, May – June 2017 International Journal of Advanced Research in Computer Science REVIEW ARTICLE Available Online at www.ijarcs.info © 2015-19, IJARCS All Rights Reserved 2804 ISSN No. 0976-5697 THE NOTORIOUS NINE: TOP CLOUD COMPUTING SECURITY CHALLENGES IN 2017 Abdul Majid Farooqi School of Engineering Sciences and Technology (SEST) Jamia Hamdard, Hamdard University New Delhi, India Tabrez Nafis School of Engineering Sciences and Technology (SEST) Jamia Hamdard, Hamdard University New Delhi, India Kafiyah Usvub School of Engineering Sciences and Technology (SEST) Jamia Hamdard, Hamdard University New Delhi, India Abstract:Unlimited storage, virtual hardware, a vast amount of computing power, low cost, location-independent data access. These are some unique features that are provided by the cloud computing, despite all these great benefits cloud computing facing criticism from the experts regarding its security, many organizations want to move their sensitive and confidential data to the cloud, but still in 2017 they are confused, they are expending lots of money to buy expensive hardware and software for their organization, rather than they buy a cloud storage or cloud computing power at very cheap price. So, what’s the reason behind it? Why are they feeling fear to involve in cloud technologies? In this paper, we will try to find out the answers to these questions and will discuss some top cloud security challenges that are currently cloud industry is facing. Keywords:Cloud Computing, Cloud Security, Cloud Security Challenges. I. INTRODUCTION As cloud computing becoming more popular day by day across the globe due to its tremendous features like resource pooling and elasticity, self-service, and on-demand services, pricing, quality of service, unlimited storage, ultimate computing power, location independence, anywhere access, virtualizationetc. it creates more security issues and challenges to the experts, many people are accepting cloud computing and its services for their businesses and transferring all their personal and professional data to the cloud for easy access, but one fear always remain in their hearts, one scary question always confuses their minds. How much their data is secured in the cloud? Are they 100% protected? In the beginning of cloud computing,it couldn’t gain that much popularity and acceptance among people due to its security issues and challenges, with passing years cloud technologies emerged rapidly and it is ruling the world now.Cloud Security Alliance (CSA) found that more than 70% of the world’s business occupied by cloud computing [1]. Although acceptance of cloud computing has become more common, security challenges still exist. Here in this paper,we will discuss cloud computing and its type and service models, also, we will discuss top cloud computing security threats in 2017 called “The Notorious Nine”. Our paper is structured as follows: InSection 2 we will discuss related research or related work and will talk what other people have done in their paper related to cloud security and challenges. Section 3 is based on an overview of cloud computing, in this section, we will discuss cloud and cloud computing definition, types of cloud and cloud service models. Section 4 will be based on security challenges in cloud computing, in this section, we will discuss top nine security issues of cloud computing called The Notorious Nine. In section 5 we will conclude our paper. II. RELATED WORK Priya Anand [2] gives security challenges of cloud computing, she has also suggested a pattern-based security framework for cloud computing and defined the characteristics of the security pattern system. Napoleon C. Paxton [1] talks about three major security challenges of cloud computing: 1. Data Breaches, 2. The Hijacking of account, 3. Multitenancy. He also purposed a solution to these threats. Khalid EI Makkaoui [19] proposed a new cloud security and privacy model into layers that can help cloud providers to identify and classify different cloud security and privacy issues, to make the difference between various sources of cloud threats, and to adopt necessary countermeasures in order to build confidence in cloud services and also to provide secure services. Also, he presented in his paper some security threats and attacks and proposed some countermeasures. Rabi Prasad Padhy [20] discussed various models of cloud computing, security issues and research challenges in cloud computing. III. OVERVIEW OF CLOUD COMPUTING The word cloud represents as the internet or inter-connected computer systems or simply a giant network system. Cloud (Data Centers) exists at certain remote locations mostly hidden from the user, the user doesn’t know where his data is saved. It is providing many services over the internet or over the network, such as public networks and private networks, for