In the last part of cloud computing we have seen what are the three Service models of cloud computing and some of the important characteristics of cloud computing. And in this part of cloud computing we will see the deployment models of cloud computing, security issues in cloud computing and some important file systems.

First let’s start with the deployment models of cloud. There are three deployment model of cloud computing and they are-

1) Private Cloud

2) Public Cloud

3) Hybrid Cloud

Let’s start with the first deployment model which is Private Cloud

Private Cloud- Most of the organization have a lot of confidential data and should not be disclosed to other persons. Hence when we store such a data in public its potential risk increases and hence Private Cloud is used for such an organization. This type of cloud can be managed internally or by third party.

Advantages of this model is that it provides greater security and high availability. It is also fault tolerant as compared to public cloud.

Private Cloud- It is one of the basic (standard) model of cloud computing and is called as shared cloud. This type of cloud is available to the user on the basis of subscription or the services can also be available free. Complexity of this type of cloud is less. The services in the cloud can be developed and deployed by the consumer and also the capital required for such development is also less.

Hybrid Cloud- This type of cloud is combination of two or more cloud. Hence it provides benefits of all clouds. It is possible to move data between two or more deployment model of cloud. This type of cloud is maintained by cloud provider.

Security Issues in Cloud Computing-

1) At infrastructure level-

The system admin at infrastructure level can attack the system as he has access to the system. To avoid the security issues at this level various measures can be taken as follows-

• All accessing rights to system should not be given to single person.
• Trusted Computing Group at infrastructure level provides security to the system.

2) At platform level-

Security at this level depends on three important aspects and they are- Confidentiality, Integrity and Availability. Also proper authentication must be provided to have more security.

3) At data level-

Cloud users upload their sensitive data on the storage provided in cloud. Hence more security is to be provided at this level. Data should be encrypted when it is to be uploaded on cloud. At time of downloading it should be decrypted with proper key management. Data should also be protected from losses or corruption.

Figure depicts one of the way in which security is provided in the cloud data storage.