What is cloud computing?

CLOUD COMPUTING Cloud computing is the on demand availability of computer system resources, especially data storage (cloud storage) and computing power, without direct active management by the user. Large clouds often have functions distributed over multiple locations, each location being a data center. Cloud computing relies on sharing of resources to achieve coherence[clarification needed] and economies of scale, typically using a "pay as you go" model which can help in reducing capital expenses but may also lead to unexpected operating expenses for unaware users. Service Models There are five service models out of them top 3 are widely used and most of the content ofinternet uses these kind of service models. 1. Infrastructure as a Service (Iaas) 2. Platform as a Service (PaaS) 3. Software as a Service (SaaS) 4. Mobile backend as a Service (MBaaS) 5. Serverless computing or Function as a Service (FaaS) Control comparison between all major models In the following image we have the comparison between the different service models which gives us the insight about the amount of access and the control we have while using this service models. Major Deployment Models To deply the cloud architecture there are three ways we could do. With private being the most used till today organizations are moving to use Hybrid cloud more nowadyas and also migrating towards also. The following images displays that what each cloud models offer to the users, The following image puts more emphasis on the comparison across all three cloud models/ Read more about them here, 1. Private Cloud 2. Public Cloud 3. Hybrid Cloud Other Deployment Models 1. Community Cloud 2. Distributed Cloud 3. Multi Cloud 4. Poly Cloud 5. HPC Cloud Security and Privacy Cloud computing poses privacy concerns because the service provider can access the data that is in the cloud at any time. It could accidentally or deliberately alter or delete information. Many cloud providers can share information with third parties if necessary for purposes of law and order without a warrant. That is permitted in their privacy policies, which users must agree to before they start using cloud services. Solutions to privacy include policy and legislation as well as end users' choices for how data is stored. Users can encrypt data that is processed or stored within the cloud to prevent unauthorized access. Identity management systems can also provide practical solutions to privacy concerns in cloud computing. These systems distinguish between authorized and unauthorized users and determine the amount of data that is accessible to each entity. The systems work by creating and describing identities, recording activities, and getting rid of unused identities. According to the Cloud Security Alliance, the top three threats in the cloud are Insecure Interfaces and APIs, Data Loss & Leakage, and Hardware Failure—which accounted for 29%, 25% and 10% of all cloud security outages respectively. Together, these form shared technology vulnerabilities. In a cloud provider platform being shared by different users, there may be a possibility that information belonging to different customers resides on the same data server. Additionally, Eugene Schultz, chief technology officer at Emagined Security, said that hackers are spending substantial time and effort looking for ways to penetrate the cloud. "There are some real Achilles' heels in the cloud infrastructure that are making big holes for the bad guys to get into". Because data from hundreds or thousands of companies can be stored on large cloud servers, hackers can theoretically gain control of huge stores of information through a single attack—a process he called "hyperjacking". Some examples of this include the Dropbox security breach, and iCloud 2014 leak. Dropbox had been breached in October 2014, having over 7 million of its users passwords stolen by hackers in an effort to get monetary value from it by Bitcoins (BTC). By having these passwords, they are able to read private data as well as have this data be indexed by search engines (making the information public). There is the problem of legal ownership of the data (If a user stores some data in the cloud, can the cloud provider profit from it?). Many Terms of Service agreements are silent on the question of ownership. Physical control of the computer equipment (private cloud) is more secure than having the equipment off site and under someone else's control (public cloud). This delivers great incentive to public cloud computing service providers to prioritize building and maintaining strong management of secure services. Some small businesses that don't have expertise in IT security could find that it's more secure for them to use a public cloud. There is the risk that end users do not understand the issues involved when signing on to a cloud service (persons sometimes don't read the many pages of the terms of service agreement, and just click "Accept" without reading). This is important now that cloud computing is becoming popular and required for some services to work, for example for an intelligent personal assistant (Apple's Siri or Google Now). Fundamentally, private cloud is seen as more secure with higher levels of control for the owner, however public cloud is seen to be more flexible and requires less time and money investment from the user. To resolve these king of security and privacy concerns we could come up with the cloud service which could be clubbed up with Blockchain Technology Limitations and Disadvanatages There are immense potential in cloud computing and features which could be extracted and which makes the developer life easy and easy to extend the resources power with minimal investment. 1. Downtime 2. Security and Privacy 3. Vulnerablity to attack 4. Limited control and flexiblity 5. Vender Locking 6. Cost Concerns