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}{% \vskip8pt \textcolor{GJMediumGrey}{\rule{\textwidth}{2pt}} \vskip16pt } \usepackage[absolute,overlay]{textpos} \makeatother \usepackage{lineno} \linenumbers \begin{document} \author[1]{Anukrati Dubey} \author[2]{Sandeep Sahu} \affil[1]{ Shriram Institute of Technology Jabalpur Madhya Pradesh India} \renewcommand\Authands{ and } \date{\small \em Received: 15 April 2013 Accepted: 5 May 2013 Published: 15 May 2013} \maketitle \begin{abstract} Cloud has now become the essential part of the web technology and fast growth of cloud computing technique making it worth for the companies to invest in cloud. Growth of number of clouds is requiring inter cloud communication as concept of multi cloud or hybrid cloud is also spreading quickly. With this fast growth, more and more challenges are arising in the field of cloud computing. Various researchers are focusing on cloud oriented challenges and lots of research works are going on in this field. With emergence of cloud computing, the term "Hybrid Topology" or "Hybrid Deployment" is becoming more and more common. A "Hybrid Cloud" is group of clouds you join different cloud deployments into one connected cluster. Another area of research is to focus on communication between a cloud and non cloud computing system. Hybrid Cloud computing mainly deals with working of data centers where different software are installed with huge of growing data to provide information to the users of the system.The techniques which can be used in hybrid cloud securities can be built around the encryption and decryption of data, key based security algorithms which are mainly oriented on authentication and authorization techniques as in wired and wireless networks. One such mechanism is to share the challenge text between the clouds before actual communication should start for authentication. The various works done in this area till date are oriented on other techniques of security between the two or more clouds in a hybrid cloud. \end{abstract} \keywords{cloud computing; hybrid cloud; challenge text; security.} \begin{textblock*}{18cm}(1cm,1cm) % {block width} (coords) \textcolor{GJBlue}{\LARGE Global Journals \LaTeX\ JournalKaleidoscope\texttrademark} \end{textblock*} \begin{textblock*}{18cm}(1.4cm,1.5cm) % {block width} (coords) \textcolor{GJBlue}{\footnotesize \\ Artificial Intelligence formulated this projection for compatibility purposes from the original article published at Global Journals. However, this technology is currently in beta. \emph{Therefore, kindly ignore odd layouts, missed formulae, text, tables, or figures.}} \end{textblock*} \let\tabcellsep& \section[{Introduction}]{Introduction}\par loud computing is becoming a buzz word in computer industry and everyone is looking to associate in one way or other with this brand new concept. Cloud computing is a very current topic and the term has gained a lot of traction being sported on advertisements all over the Internet from web space hosting providers, through data centers to virtualization software providers.\par Special emphasis is put on the critical examination of each strategy as now more than ever in the face of the global economic crisis, companies face higher refinancing and investment costs and as any company thinking about adopting or moving to cloud computing technology would do in practice; short-tomedium term disadvantages of the technology have to V i e w \section[{Cloud Computing}]{Cloud Computing}\par Abstract -Cloud has now become the essential part of the web technology and fast growth of cloud computing technique making it worth for the companies to invest in cloud. Growth of number of clouds is requiring inter cloud communication as concept of multi cloud or hybrid cloud is also spreading quickly. With this fast growth, more and more challenges are arising in the field of cloud computing. Various researchers are focusing on cloud oriented challenges and lots of research works are going on in this field. With emergence of cloud computing, the term "Hybrid Topology" or "Hybrid Deployment" is becoming more and more common. A "Hybrid Cloud" is group of clouds you join different cloud deployments into one connected cluster. Another area of research is to focus on communication between a cloud and non cloud computing system. Hybrid Cloud computing mainly deals with working of data centers where different software are installed with huge of growing data to provide information to the users of the system.\par The techniques which can be used in hybrid cloud securities can be built around the encryption and decryption of data, key based security algorithms which are mainly oriented on authentication and authorization techniques as in wired and wireless networks. One such mechanism is to share the challenge text between the clouds before actual communication should start for authentication. The various works done in this area till date are oriented on other techniques of security between the two or more clouds in a hybrid cloud.\par ? Integration-as-a-Service ? Security-as-a-Service ? Management/Governance-as-a-Service ? Testing-as-a-Service b) Hybrid Cloud Computing 1. A hybrid cloud is a composition of at least one private cloud and at least one public cloud. A hybrid cloud is typically offered in one of two ways: a vendor has a private cloud and forms a partnership with a public cloud provider, or a public cloud provider forms a partnership with a vendor that provides private cloud platforms. 2. A hybrid cloud is a cloud computing environment in which an organization provides and manages some resources in-house and has others provided externally. For example, an organization might use a public cloud service, such as Amazon Simple Storage Service (Amazon S3) for archived data but continue to maintain in-house storage for operational customer data. Ideally, the hybrid approach allows a business to take advantage of the scalability and cost-effectiveness that a public cloud computing environment offers without exposing mission-critical applications and data to third-party vulnerabilities. This type of hybrid cloud is also referred to as hybrid IT. \section[{Challenges in Hybrid Cloud Computing}]{Challenges in Hybrid Cloud Computing}\par Here are some challenges to consider when setting up hybrid clouds: i. On Demand Startup and Shutdown Your infrastructure must be able to start up and shutdown cloud nodes on demand. Usually you should have some policy implemented which listens to some of your application characteristics and reacts to them by starting or stopping cloud nodes. In simplest case, you can react to CPU utilization and start up new nodes if main cloud gets overloaded and stop nodes if it gets under loaded. \section[{ii. Cloud-based Node Discovery}]{ii. Cloud-based Node Discovery}\par The main challenge in setting up regular discovery protocols on clouds is that IP Multicast is not enabled on most of the cloud vendors (including Amazon and GoGrid). Your node discovery protocol would have to work over TCP. However, you do not know the IP addresses of the new nodes started on the cloud either. To mitigate that, you should utilize some of the cloud storage infrastructure, like S3 or SimpleDB on Amazon, to store IP addresses of new nodes for automatic node detection. \section[{Latency}]{Latency}\par Communication between clouds may take longer than communication between nodes within the same cloud. Often, communication within the same cloud is significantly slower than communication within local data center. Your middleware layer should properly react to and handle such delays without breaking up the cluster into pieces. \section[{Reliability and Atomicity}]{Reliability and Atomicity}\par Many operations on the cloud are unreliable and non-transactional. For example, if you store something on Amazon S3 storage, there is no guarantee that another application can read the stored data right away. There is also no way to ensure that data is not overwritten or implement some sort of file locking. The only way to provide such functionality is at application or middleware layers. \section[{II.}]{II.} \section[{Existing System}]{Existing System}\par Paper \hyperref[b3]{[4]} states that Cloud computing is setting off great changes in the IT industry. There are more and more researches on cloud computing. And this paper focuses on cloud computing too. At the beginning this paper describes the characteristics and definitions of cloud computing, and then introduced its services patterns (including SaaS, PaaS and IaaS) and deployment patterns (including public cloud, private cloud and hybrid cloud), at the end lists the cloud security challenges that cloud computing faces.\par Security problems faced by the cloud system about in the following five aspects:\par ? First, face more security attacks: due to the vast amounts of user data stored in the cloud system, for There is a need to solve the problem that secure deployment of cloud platform based on the virtual machine architecture. ? Third, ensure continuity of the cloud platform services and high availability of user data and business: Amazon data center downtime event, Google's Gmail failing to use event and so on are associated with cloud computing availability. To a certain extent, the events above discourage the enthusiasm of the enterprise to use public cloud. ? Fourth, ensure the safety and privacy of user data: user data stored in the cloud system, for malicious attacks, the primary purpose is to get user privacy, and then to obtain economic benefits. ? Fifth, perfect the cloud standards: Interest-oriented IT development process leads to cloud standards exist everywhere. Many manufacturers have defined their own application standards and data formats, forcing the user deploying IT system and their own business in accordance with the framework set by different service provider \hyperref[b3]{[4]}.\par With the advance of cloud computing, hybrid cloud that integrate private and public cloud is increasingly becoming an important research issue. Migrating cloud applications from a busy host to an idle host needs an efficient way to guarantee the performance in the geographical heterogeneous cloud environment \hyperref[b0]{[1]}.\par From the studies of various research papers and works done by various researchers it has been found that following are the major areas of focus in the field of cloud computing:\par 1. Defining Architecture: on the basis of the application areas. 2. Security of communication over the cloud. \section[{Integration of services on various layers. 4. Inclusion of Various network and communication devices being developed rapidly [1]}]{Integration of services on various layers. 4. Inclusion of Various network and communication devices being developed rapidly [1]}\par III. \section[{Proposed Algorithm}]{Proposed Algorithm}\par This work proposes a secured intra cloud communication mechanism in which it is being tried to keep the data more secured over the intra cloud communication using a challenge text based communication. Various Steps involved are as follows:\par Step 1: Cloud 'A' has to communicate with Cloud 'B'.\par (Both 'A' and 'B' may be public, private or combination).\par Both have a trusted environment already created between them using SLA.\par Step 2: Cloud 'A' sends a data request (DRQ) to Cloud 'B'.\par Step 3: Cloud 'B' receives the DRQ and sends a challenge text (RID) encrypted using RSA algorithm, to Cloud 'A'.\par Step 4: Cloud 'A' receives the RID and decrypts the same using its public key. The decrypted text (VID) is sent to the Cloud 'B'.\par Step 5: Cloud 'B' if founds that the key is matching, it will send the encrypted data to Cloud 'A' as desired by the Cloud 'A'.\par Step 6: Cloud 'B' if founds that the key is not matching, it will reject the request instantly. DRQ-Data Request RID-Reveal Identification VID -Verify Identity IV. \section[{Results}]{Results}\par The algorithm is performing better in all situations such as a cloud is performing mal activities, cloud become malicious after a while or a cloud is not at all malicious. From the graph in figure 4 time taken in processing of data after verification process is completed is shown. The graph shows that as the number of clouds increase and the data transferred between them is also increased and it results in linear increase in time with the number of clouds. This is also as per the expected outcome over the cloud environment.\par Table \hyperref[tab_0]{1} show the comparison of the works of the various researchers including the proposed work and from the table it is seen that the proposed work provides better number of services in terms of cloud security. It supports multi-clouds and hybrid cloud and provides both the data and storage oriented services. \section[{Conclusion and Future Work}]{Conclusion and Future Work}\par Since cloud connects to thousand and thousand people over internet or intranet on pay per basis, therefore security of the cloud is a focused are for researchers and with the growth of the cloud computing and hybrid computing, requirements for security are increasing heavily. The proposed work is expected to provide a good security infrastructure over cloud.\par One mechanism is to share the challenge text between the clouds before actual communication should start for authentication. The various works done in this area till date are oriented on other techniques of security between the two or more clouds in a hybrid cloud.\par Cloud Computing is facilitating users around the world for the best of the services available across the world on their machines through web. It is beneficial for both the service providers (they get huge clientele) and clients (they get all available services).\par For data security and privacy protection issues, the fundamental challenges are separation of sensitive data and access control. Our objective is to design a set of unified identity management and privacy protection frameworks across applications or cloud computing services. \begin{figure}[htbp] \noindent\textbf{}\includegraphics[]{image-2.png} \caption{\label{fig_0}}\end{figure} \begin{figure}[htbp] \noindent\textbf{3}\includegraphics[]{image-3.png} \caption{\label{fig_1}3 .}\end{figure} \begin{figure}[htbp] \noindent\textbf{}\includegraphics[]{image-4.png} \caption{\label{fig_2}}\end{figure} \begin{figure}[htbp] \noindent\textbf{3}\includegraphics[]{image-5.png} \caption{\label{fig_3}Figure 3 :}\end{figure} \begin{figure}[htbp] \noindent\textbf{}\includegraphics[]{image-6.png} \caption{\label{fig_4}B}\end{figure} \begin{figure}[htbp] \noindent\textbf{1} \par \begin{longtable}{P{0.16826530612244897\textwidth}P{0.06765306122448979\textwidth}P{0.06244897959183674\textwidth}P{0.03816326530612245\textwidth}P{0.1370408163265306\textwidth}P{0.0017346938775510206\textwidth}P{0.24979591836734696\textwidth}P{0.06418367346938776\textwidth}P{0.06071428571428571\textwidth}} Volume XIII Issue IV Version I\tabcellsep Ref\tabcellsep Year\tabcellsep Cloud Security\tabcellsep \multicolumn{2}{l}{Addressed Security Risks Data Integrity Data Intrusion Service Availability}\tabcellsep Privacy/ Security Mechanism\tabcellsep Type f Cloud Single Cloud Multi\tabcellsep Type Of Service Cloud Storage\\ D D D D D D D D )\tabcellsep \tabcellsep \tabcellsep \tabcellsep \tabcellsep \tabcellsep \tabcellsep \tabcellsep \\ (\tabcellsep \tabcellsep \tabcellsep \tabcellsep \tabcellsep \tabcellsep \tabcellsep \tabcellsep \\ Global Journal of Computer Science and Technology\tabcellsep {}[11] [17] [22] [25] [30] [55]\tabcellsep 2010 2010 2010 2010 2009\tabcellsep ? ? ? ?\tabcellsep ? ?\tabcellsep ?\tabcellsep ICStore,(clientcentric distributed protocols) SPORC, (fork) cryptography homomorphic token + erasure-coded\tabcellsep ? ? ?\tabcellsep ? ? ?\\ \tabcellsep {}[7]\tabcellsep 2007\tabcellsep \tabcellsep ?\tabcellsep \tabcellsep PDP schemes\tabcellsep \tabcellsep \\ \tabcellsep {}[19]\tabcellsep 2007\tabcellsep ?\tabcellsep \tabcellsep \tabcellsep \tabcellsep ?\tabcellsep ?\end{longtable} \par {\small\itshape [Note: BChallenge Token based Security for Hybrid Clouds]} \caption{\label{tab_0}Table 1 :}\end{figure} \footnote{© 2013 Global Journals Inc. (US) Year} \footnote{© 2013 Global Journals Inc. (US) Year} \footnote{© 2013 Global Journals Inc. (US) Year} \backmatter \hyperref[b4]{[5]} \par 2011\par DepSky,(Byzantine + secret sharing + cryptography) \begin{bibitemlist}{1} \bibitem[Fan]{b4}\label{b4} \textit{}, Chih-Tien Fan . \bibitem[Wang]{b5}\label{b5} \textit{}, Wei-Jen Wang . \bibitem[Chen et al.]{b10}\label{b10} ‘A Systematic Framework Enabling Automatic Conflict Detection and Explanation in Cloud Service Selection for Enterprises’. Chunqing Chen , Shixing Yan , Guopeng Zhao . 978-0-7695-4755-8 © 2012 IEEE DOI 10.1109/ CLOUD.2012.95. \textit{2012 IEEE Fifth International Conference on Cloud Computing}, (Bu Sung Lee) \bibitem[Chang ()]{b6}\label{b6} Yue-Shan Chang . \textit{High Performance Computing and Communications (HPCC), 2011 IEEE 13th International Conference on Publication Year}, (Page(s) 2011. p. . \bibitem[Yandong et al. ()]{b3}\label{b3} ‘Cloud Computing and Cloud Security Challenges’. 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