Question

• Define cloud computing.
• List and briefly define three cloud service models.
• What is the cloud computing reference architecture?
• Describe some of the main cloud-specific security threats.

Answer 1

1. In order to define and explain what is cloud computing, let me first give you an example- Imagine you want to play high-end games on your device but your device does not support that types of games or you want to store large amount of data on your device but there is not sufficient storage space on your device or you want to use those software which are not installed on your system or you need to buy them to use that software.

To solve all these problems there are 2 options, first is to buy a whole new setup having support for all types of high-end games and a large storage space and buy all the licences required to use those software. Second and most preferable way is to do our work on someone else's computer(or servers) which meet our all requirements through internet and get the work done on there machines by using their Software and Hardware. The idea of cloud computing is just same.

So. the simple definition of Cloud Computing is that we use services of remote servers instead of local servers for storing our data, to use software and applications that are not installed our device, if we need high processing capability.

2.  There are 3 service models of cloud computing

• IaaS (Infrastructure as a Service)
• PaaS (Platform as a Service)
• Saas (Software as a Service)

a. IaaS - In this model, the client is given all the administrative rights to select their own Operating System. They are provide with a unique IP address. They are provided with VLANs to group devices that are physically not on same place. They need to setup most of the security parameters themselves. Amazon AWS , Google Cloud Platform, Microsoft Azure are the most popular cloud service providers.

b. PaaS - In model is more useful for application developers who want an environment to deploy their applications on the cloud and use various development tools to perform testing of their applications or to develop new applications using various tools available on cloud. Google App Engine is a popular provider of PaaS service.

c. SaaS - This type of model is mainly used by end-users like us. In this, users can use the software which are deployed on the servers by the cloud service providers. End-users do not need to install those software on their device because all the resources are managed by vendors. Example- We can use MS Office, Photoshop and many other software online without even installing them on our devices.

3.  NIST gave the architecture for the cloud computing reference model. This models contains 5 essential characteristics, 3 service models, 3 deployment models.

a. 5 Essential Characteristics

1. On-demand self-service - This means that an individual can get cloud services anytime, whenever they want to use them.
2. Broad network access - Cloud services can be accessed from various range of devices such as from mobile phones, PC, laptop, etc.
3. Resource Pooling - The services of cloud service provider are pooled to provide those services to multiple users simultaneously over the world using a multi-tenant model.
4. Rapid Elasticity - Users can scale up or down the services according to their demand.
5. Metered Service - Customers have to pay for how much they use as cloud resources are monitored all the time.

b. 3 Service Models

1. PaaS - In model is more useful for application developers who want an environment to deploy their applications on the cloud and use various development tools to perform testing of their applications or to develop new applications using various tools available on cloud. Google App Engine is a popular provider of PaaS service.
2. SaaS - This type of model is mainly used by end-users like us. In this, users can use the software which are deployed on the servers by the cloud service providers. End-users do not need to install those software on their device because all the resources are managed by vendors. Example- We can use MS Office, Photoshop and many other software online without even installing them on our devices.
3. SaaS - This type of model is mainly used by end-users like us. In this, users can use the software which are deployed on the servers by the cloud service providers. End-users do not need to install those software on their device because all the resources are managed by vendors.

c. 3 Deployment models

1. Public cloud - In this, the cloud services are made available for the use of general public and that services are owned by an organization providing cloud services.
2. Private cloud - In this, cloud infrastructure is used by a single organization for their own use. There may be some company who is managing that cloud.
3. Hybrid cloud - This models combines the best features of both the cloud to provide much better cloud services to their customers.

4.  Some of the cloud-specific security threats are:

• Data breach- Sometimes, the confidentiality and integrity of our data is lost which our data get in the hands of some unauthorized persons.
• Data Loss - Most of the cloud service providers must ensure that in case the data gets lost, they must provide some backup to recover tat lost data.
• Malicious Insider - In this,  an organisation might appoint an employee, and is granted all access to manage the confidential data of their users Such permissions can lead to various data security issues.