Trust and Reliability Management in Large-Scale Cloud Computing Environments

Introduction

This chapter discourses the various trust models for performance improvement in the cloud environment. Cloud is the best example of a distributed system where different vendors/services provide collaboration to provide services to the client. The service providers may be located at different geographical locations, which also mean that all the service providers do not provide the same quality of service to users in terms of computing and security. In such scenarios where the user pays for the services provided the controller has to select the service provider based on the requirement and cost that the user has been charged for. Trust models resolve the problem of judging any service provider by its past performance and help in selecting the correct service provider for the client to complete the task within the SLA (Service Level Agreement) between user and service provider. The trust model ensures that all the requests are completed and the user gets the best quality of service. Trust means a firm belief, confidence, and reliance in something that can deliver an expected behavior with high reliability. This belief allows you to rely on something in the future for more tasks (Khan, 2010; Gambetta, 2000; Perez,2009; Bret, 2009). Cloud computing supports various types of models like public, private, and hybrid models. A public and hybrid model public and hybrid model has to face the problem of trust. As given in figure 1 we have assumed that private cloud stores important and sensitive data in soft Com but the other public cloud provides the capability to compute and process the data. Now the issue of trust becomes a problem because all the service providers are at different locations like 1) Boston server which provides a temporary storage 2) China server is providing processing service 3) Rome server provides filers and other processing. The issue is that the secured data will be stored on servers with low reliability and which cannot be trusted, in this case, trust model solves the problem by evaluating the servers and provides you the reliability of the server which helps to decide where to process the data and temporarily saved. Private cloud does not deal with such issues because all the servers are owned by single service providers may be at different locations or cities.

Figure 1.

cloud computing- sample example (Khan, 2010)

Figure 2.

Issues addressed by trust models

Trust model in cloud majorly deals with two issues:

• 1.

  Security Challenges.

  • a.

    Control of Data

  • b.

    Control of process

  • c.

    Security profile

• 2.

  Scheduling and load balancing.

  • a.

    Certification

  • b.

    capabilities

Figure 2 shows various issues that are addressed by trust models in cloud computing some of them are listed above.