Chapter 5.3: Data Security in Cloud Computing

1 Chapter : data Security in Cloud ComputingShucheng Yu1, Wenjing Lou2, and Kui Ren31 University of Arkansas at Little Rock, AR, USA2 Virginia Polytechnic Institute and State University, VA, USA3 Illinois Institute of Technology, IL, Computing has come into reality as a new IT infras-tructure built on top of a series of techniques such as distributed comput-ing, virtualization, etc. Besides the many benefits that it can bring forth, Cloud Computing also introduces the difficulty of protecting the securityof data outsourced by Cloud users.

2 This Chapter will first study the basicconcepts and analyze the essentials of data Security issues pertaining toCloud Computing . Then we elaborate on each issue by discussing its na-ture and existing solutions if available. Specifically, we will emphasize onissues of protecting data confidentiality/integrity/availability, securingdata access and auditing, and enforcing the regulations and compliancesregarding to data Security and Computing , data Security , confidentiality, integrity, avail-ability, access control1 OverviewCloud Computing is a new IT infrastructure in which Computing resources areprovided as a utility to Cloud users in the pay-as-you-go manner.

3 By integrat-ing techniques such as Service Oriented Architecture (SOA), virtualization, dis-tributed Computing and etc, Cloud Computing offers elastic, on-demand and mea-sured services to Cloud users anytime anywhere whenever Internet is available,and enable them to enjoy the illusionary unlimited Computing resources. Theservices provided by the Cloud can be at different levels of the system stack,which can be described by the terminology of X as a service (XaaS) whereX could be Software, Infrastructure, Hardware, Platform and etc.

4 For example,Amazon EC2 provide Infrastructure as a service and allow Cloud users to managevirtual machine instances and control almost the entire software stack above theOS kernel; Google AppEngine provides Software as a service which is targetedat traditional web applications; Microsoft Azure offers services which are inter-mediate between AppEngine and EC2. By deploying applications in the Cloud , Cloud users are able to enjoy massive and elastic Computing resources withoutthe large capital outlays in building their own data centers.

5 Such a fact will sig-nificantly benefit the IT industry, especially small and medium IT enterprises,letting alone individuals, who were greatly limited by Computing resources. Forthis reason, Cloud Computing is believed to have the potential to shape the ITindustry in the What is Cloud Computing ?Although the benefits of Cloud Computing are obvious, it is not trivial to pro-vide a concrete definition for Cloud Computing due to its intrinsic the date when this book is written, there is no standardized definition ofthe termcloud computingexcept several attempts by leading institutions andstandard organizations.

6 A research group from the University of California atBerkeley [19] defines Cloud Computing as below: Cloud Computing refers to both the applications delivered as services over theInternet and the hardware and systems software in the datacenters that providethose services. The services themselves have long been referred to as Software asa Service (SaaS). The datacenter hardware and software is what we will call aCloud. When a Cloud is made available in a pay-as-you-go manner to the generalpublic, we call it a Public Cloud ; the service being sold is Utility Computing .

7 Weuse the term Private Cloud to refer to internal data centers of a business or otherorganization, not made available to the general public. Thus, Cloud Computingis the sum of SaaS and Utility Computing ..- Above the Clouds: A Berkeley View of Cloud Computing NIST [15] gives the following unofficial definition of Cloud Computing : Cloud Computing is a pay-per-use model for enabling available, convenientand on-demand network access to a shared pool of configurable Computing re-sources ( , networks, servers, storage, applications and services)

8 That canbe rapidly provisioned and released with minimal management effort or serviceprovider NIST unofficial draftNotwithstanding that there is no such a unique definition of Cloud Computing ,these works together do outline several most important characteristics of cloudcomputing: 1) Computing resources at different level of the system stack areprovided as Cloud services in the pay-as-you-go manner like traditional utilityservices, , Software-as-a-Service (SaaS), Platform-as-a-Service (PaaS) andInfrastructure-as-a-Service (IaaS).

9 Cloud users just need to pay for what theyhave actually used. 2) Rapidly elastic and scalable resources are available tocloud users. Cloud users are able to launch more Computing resources at peaktime and release them at nonpeak times, and saves their capital expenditurein hardware/software to deal with the fluctuation in workloads. 3) The servicesare provided in the on-demand manner and can be configured by Cloud usersthemselves. This makes it very convenient for Cloud users to access Cloud servicesas they no longer need to interact with the system administrator and go throughthe usually lengthy processing routines.

10 4) Cloud services are made accessiblevia the Internet. Cloud users can launch these services on any platform thatsupports web techniques. 5) Computing resources are pooled and provided tocloud users independent of their locations. Besides these essential characteristics,3 Cloud Computing also has other properties such as multi-tenant architecture, , applications of numerous customers may co-run or co-exist on the samephysical device. According to its ownership and the technical architecture, CloudComputing can be categorized asPublic Cloud ,Private Cloud ,Hybrid CloudandCommunity Cloud .