IJISET - International Journal of Innovative Science, Engineering & Technology, Vol. 2 Issue 4, April 2015.   www.ijiset.com ISSN 2348 – 7968 333 Survey On Security Threats In Data Storing & Sharing In Cloud Environment Seema Tahalyani 1 and Dr. S.M Ghosh 2 1 CSE Department, Rungta College of Engineering & Technology, Bhilai, Chhattisgarh, India 2 CSE Department, Rungta College of Engineering & Technology, Bhilai, Chhattisgarh, India Abstract Cloud Computing is a next generation model which has gained popularity in recent years. Cloud computing paradigm is based on Internet that provides various provisions like sharing of configurable computing resources, on demand services any where any time and at any place across the globe. A key trait of cloud computing services is outsourcing and sharing of user’s data. Cloud provides the facility of huge amount of storage space for data but at the same time users doesn’t have the authority to control the outsourced data. In the shared tenancy system like cloud various security concerns regarding data storing and sharing arise which are major issues of concerns. In this paper, we are going to present an analytical study of cloud computing model and throw light on various services provided by cloud. Further we are going to focus on several security threats that arise during data storage and data sharing in cloud. Keywords: Cloud computation, Service Models, Deployment model, reference architecture, data security, and data sharing. 1. Introduction Cloud computing model is a next generation paradigm for IT industry. Cloud computing model use computer technology and is entirely based on Internet without which its existence become impossible. Its architecture contains large data centers that are converted into pools of computing resources. Storing data into cloud is a convenient way for the users to get rid from the complexity of hardware and other resource maintenance and management. The customizable computing resources are made available to the users as per their need by the Cloud Service Providers (CSP). In other words, one can access anything through cloud from anywhere from any place and from any computer on a per use basis [1]. The vision that various utilities based services made easily available to the users on the basis of on demand usage is an innovative concept. Cloud computing platform hides the complexity and details of the underlying infrastructure from users and applications by providing very simple graphical interface or API (Applications Programming Interface). The computing resources may be networks, hardware and software, servers, storage devices, applications etc. Figure 1.1 shows how various resources are connected in the cloud for sharing purpose. Cloud has the property of elasticity which means pay only for those resources that are needed [2]. Fig. 1 Sharing of various resources in cloud computing Evolution of Cloud Computation is still going on and there is no widely accepted definition of it. But according to NIST (National Institute of standards and technology) cloud computation is defined as [17]: “Cloud computing is a model for enabling ubiquitous, convenient, on-demand network access to a shared pool of configurable computing resources (e.g., networks, servers, storage, applications, and services) that can be rapidly provisioned and released with minimal management effort or service provider interaction.” Some essential characteristics of cloud that make it unique in comparison to other traditional technologies are [2]:  On-demand self services  Broad network access  Resource Pooling  Rapid elasticity