This final step examines public cloud hosting. We move the network service outside the company's trust boundary. We talked briefly about these essential characteristics in the first module. For most of us the bottom line is that the cloud helps us build online applications that adapt quickly and transparently to changes in customer load. This flexibility requires a robust infrastructure, and some types of scaling require special forms of application architecture. We usually talk about cloud service in terms of the three service models. The models assign responsibility for development and support tasks at different levels of the system. This also assigns responsibilities for different aspects of cybersecurity. Cloud servers contain typical server components. A hardware layer provides storage, computing power, and network connections. Next comes the operating system, and a top that a middleware layer containing tools like programming languages and service libraries. At the top comes the cloud application. Computers aren't smart enough to take care of themselves, users and IT administrators tell them what to do and fix things when they break. But who fixes what in the cloud? We divide the work between the cloud provider and the cloud consumer based on the service model. A provider handles things from the hardware upwards. A full service provider will apply resources to match the service demand. The provider could allocate more processes to the operating system or more virtual hardware to the consumer's service. The consumer handles matters from the application downward, this includes configuring the client base and custom application development. The specific responsibilities are tied to the service model. Infrastructure as a service, acronym IAAS, draws the line at the operating system. The provider takes care of computer hardware and limited operating system support. The infrastructure may consist of physical machines or virtual machines. The consumer takes care of everything else. Major players dominate infrastructure as a service. Platform as a service, acronym PAAS, provides more software support. The provider maintains the hardware, the operating system, and some layers of middleware. Consumers may provide their own middleware as well as their custom applications. While the largest cloud vendors offer platform as a service as a broad offering, other providers may focus on particular languages or frameworks, like Java, Drupal, Ruby on Rails, or the JavaScript Frameworks. Two examples of platform as a service are particularly interesting. The most familiar is cloud storage, and users value its mobility and reliability. Another platform service is the container concept. A container service can install and run pre-built executable modules in a highly mobile and scalable fashion. You need to go lie down now, yes, go lie down, Jenny. Software as a service, acronym SAAS, puts most software responsibilities on the provider. The consumer takes care of configuration and enterprise specific data. Software as a service includes e-commerce vendors like eBay and service vendors like Salesforce and many vendors in between. Remaining courses in the University of Minnesota's cloud security specialization will focus primarily on infrastructure as a service and platform as a service. Vendors who offer software as a service implement their own unique security architectures. When they provide service flexibility the features often use the same mechanisms we will see in infrastructure and platform oriented cloud services. [MUSIC] Good dog.
