Introduction Cloud computing is the process of computing large farms and storage resources using the internet. We use network-centric computing and network-centric content when we use resources from distant data centers instead of our own servers. Two computing models are utility computing model in which users pay as they use the computing resources and the cloud computing model which is accepted by many IT companies. The major clouding computing delivery models are Software-as-a-Service (SaaS), Platform-as-a-Service (PaaS), and Infrastructure-as-a-Service (Iaas). They are again classified as public, private, hybrid and community cloud based on the cloud location.Network-Centric Computing and Network-Centric Content Network-centric computing and Network-centric contents have many developments like utility computing and Grid computing. Grid computing is a system in which many physical systems are arranged together for each domain. In utility computing, users can pay for the services they have used. The concept of utility computing came up due to the creation of virtual versions servers like storage and operating systems. Main advantages of utility computing are the low operational cost. This became available to any type of firm as it is a pay for use basis.Cloud computing is the next level of the utility computing. It is great for IT operations or development team to develop, built, deploy and run their application which can run faster and improve in scalability without having any concerns about the location of underlying infrastructure. With cloud we can have a good back-up in case of any failures; Applications runs quickly as there is an option of creating a separate instance for cases such as peak loads; Multiple application can be run in one computer such as VMware; Initialization and maintains cost is low. Any type of static or dynamic media irrespective of stored media or the live media is referred to content. It is assumed that the future internet will be content-centric as the development of visualized links converts internet to support the quality. With content-centric users can get back the data from the most exact location in a minimum download time. Data-intensive, network-intensive, Systems use thin-clients, Infrastructure allows workflow are the main characteristic of network-centric and content-centric. The advantages are data sharing with high security, cost reduction as we pay as we use, elasticity we can use other instances at peak-load. Peer-to-Peer System Peer-to-Peer (P2P) is a decentralized model in which each system/user has the same type of capabilities. Either user can initiate the communication request. P2P allows users to control many parameters such as a number of connections at a time, to connect or to avoid any system/user.Example by Instructor in our class – In a small firm each department is assigned to a separate domain. Human resources have a separate domain and the IT department has a separate domain and these two domains are provided with a switch and are connected to the server through routers. Types of CloudDeepening on the location of the server, size, management and user population cloud is classified as – Private cloud: This can be owned by a single organization. In this type of cloud, the organization doesn’t sell the service and it is solely used by the organization and often managed by the organization or by a third party. Private clouds are expensive and these are not suitable for small firms.· Instructors mentioned in the class that we have a Terabyte server we can start own cloud.Public cloud: This type of cloud is for the general public, basically internet. This type of cloud is not suitable for every organization. This is a pay per use service. Community cloud: This type of cloud is shared by several organizations. It is managed by the organization or a third party service.Hybrid cloud: Use of two or more different clouds is called the hybrid cloud. Depending on the firm’s purpose they can use a private and public cloud which is termed as hybrid cloud.Cloud computing delivery models Based on the service offered by the cloud, it is classified as:Software-as-a-Service (Saas): Users can access the service on the pay per use basis. Applications are provided by the service. Users do not have any control over the infrastructure of the service; they cannot manage the operations like storage of the service. Just with the simple subscription, they can use the services such as Gmail, Google Docs, Dropbox, iCloud.Platform-as-a-Service (Paas): Users can deploy an application using the programming languages supported by the service in this type of service. PaaS service users don’t have access to control the infrastructure of the cloud and they cannot manage any operations like storage, security in the cloud service. Users only have access to make any changes to the application which they have deployed in the cloud. This service is not suitable if the software is changed to improve the performance.Infrastructure-as-a-Service (Iaas): In this type of service users can deploy their application and they have access to storage, install firewall security but users don’t have access to the infrastructure of the cloud. Activities necessary to support cloud are:Ø Service management like call centers, billing, and accounting, technical support, backups, etc.Ø Security management like authentication ID, virus or malware protection, incidence response and firewalls.Ø Customer services like online support through calls and chats, personalization.Ø Development and data management which falls under Integration service.Ethical issues in CloudUnauthorized access, fail in the networks, data corruptions are major risks and it is even difficult to find out the point of cause with the complex system. In the IT organizations most of the employees such as administrators, developers have access to all employees personal data as well as customers personal data. They need the data to maintain the system and to resolve any issues. Customers trust and pay to the firm and provide their personal information and it is the firm’s duty to protect the data.We already have the sensitive data in the cloud through most of the cloud service providers. It is important to have some rules and regulations to protect the data. Though the cloud service providers provide some security, firms should come up with their security methods to protect the data in the cloud.· Instructor’s simple example in class – Even though our doors come with blots and locks, few people block the doors with chairs and other objects to ensure more security. Similarly, though the cloud service providers provide their security on firm’s data, even firms have to come up with an extra level of security by their own security methods. Cloud VulnerabilitiesVulnerability is a weakness which is used by the attackers for their personal gain. This vulnerability can be present in software, network, and system or by the security methods which we use. Most of the organizations believe that they don’t have to worry about the security of cloud service as could service providers will take care of them. This can also happen while merging into cloud service. Organizations have to consider some vulnerability such as session cookies, use of virtual machines in which physical server run many machines. We also have to consider the cloud may not be always 100% available during a power outage. Delete data from old cloud service provider. So, we have to choose a provider who can allow moving on easily when necessary. · Instructor’s important note on some of the certification which has better future scope -1) CompTIA Security+ certification 2) Certified Information Systems Security Professional (CISSP) is prior step to CompTIA Security+I believe, Systems Security Certified Practitioner (SSCP) certification is stepping stone to CISSPChallenges faced by cloud computing Security is the main challenge faced by cloud. Public cloud can’t protect the personal information which is related to health domain. In SaaS, the personal data is stored in the most vulnerable way. Though the information is stored by encrypting the data, it has to decrypt while returning back where the attacks can take place. Another challenge is resource management on cloud such as allocating capacity, balancing the load and administration creation. Standardization is the other challenge faced by the cloud.
We have to realize the complexity of the cloud and come up to face the challenges. There are many advantages using the cloud if successful in facing challenges.