A Review Study on Public Cloud Computing Environment Security Issues Manish Sharma 1 Surendra Yadav 2 Brahmdutt Bohra 3 Siddhi Saraf 4 1, 2, 3 Department of Computer Science, Maharashi Arvind College of Engineering & Research Center, Jaipur 4 Department of Electronics Instrumentation & Control, Govt. Engineering College Ajmer, Rajasthan manu13raj@gmail.com 1 , syadav66@gmail.com 2 , brahmdutt.bohra@gmail.com3, 4 siddhisaraf25@gmail.com Abstract - Cloud computing is a collection of resources and services offered through the Internet. It is an Internet-based computing, where common resources, software and information are delivered to devices and computers on-demand. Common example of cloud services is Google apps, by Google and Microsoft SharePoint. Cloud computing is receiving a good deal of attention lately because of the implications for better flexibility and availability at very minor cost. Public cloud computing is one of the several deployment models. A public cloud is a cloud computing environment where infrastructure is available to the general public on the internet. Since cloud computing share distributed resources via the network in the open environment, security problems becomes more important to develop the secure cloud computing application. In this paper, we pay attention to the key security issues and challenges in public cloud computing environment which will aware both end users and vendors to get the information about the key security issues associated with cloud computing. We also discuss the precautions taken for mitigate the security issues. Keywords: Cloud computing; Public cloud; Security; Secure cloud computing I. INTRODUCTION Cloud computing is a rising technology which recently has drawn significant attention from both industry and academics. It provides services over the internet. Using cloud computing, user can use the online services of different software instead of purchasing or installing them on their own computers. According to the definition of National Institute of Standard and Technology (NIST), cloud computing can be defined as a paradigm for enabling useful, on-demand network access to a common pool of configurable computing resources. According to Gartner [1] cloud computing can be defined as a style of computing that delivered IT capabilities „as a service‟ to end users through internet. After creation of a cloud, implementation of cloud computing varies with reference to the requirements and for the purpose it will be used. The basic service models in cloud computing are [2, 3]: Software as a Service (SaaS): Software„s are provided as a service to the clients according to their necessity, allows clients to use the services that are hosted on the server of coud. Platform as a Service (PaaS): Clients are provided platforms access, which allows them to place their own customized software„s and other applications on the clouds. Infrastructure as a Service (IaaS): Network capacity, storage, rent processing, and other basic computing resources are granted, allows consumers to manage the applications, network connectivity, storage and operating system. Fig.1: Cloud Computing Service Delivery Models Data security is a major concern for users who want to use cloud computing technology. This technology needs appropriate security principles and mechanisms to eliminate user‟s anxieties. Maximum of the cloud services users have concerns about their