Trust Management in Cloud Computing

Introduction

Cloud computing is a model for enabling ever-present, suitable, on-demand network access to a shared pool of configurable computing resources, e.g., networks, servers, storage, applications and services that can be rapidly provisioned and made available easily with minimal management effort or service provider interaction described by Siani (2012). Cloud environments provide several benefits such as reduced expenses and simplicity to service providers and service requesters. The cloud computing provides hardware and systems software resources on remote datacenters, as well as Internet gives access to the services based upon these resources. These resources dynamically scale up to match the load, using a pay-per resources business model. The significant features of cloud computing are elasticity, multitenancy, maximal resource utilization and pay-per-use. Figure 1 shows an abstracted view of the cloud computing environment with the interacting parties.

Figure 1.

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Virtualization or job scheduling techniques unifies the shared pool of resources. A host computer runs an application known as a hypervisor which creates one or more virtual machines, which simulate physical computers so faithfully, that the simulations can run any software, from operating systems, to end-user applications, Siani Pearson (2012). At hardware level processors, hard drives and network devices, are located in datacenters, independent from geographical location, which are accountable for storage and processing needs. Above this, the combination of software layers, the virtualization layer and the management layer, allow for the effective management of servers. Virtualization is an important element of cloud implementations and is used to provide the essential cloud characteristics of location independence, resource pooling and rapid elasticity. Differing from traditional network topologies, such as client–server, cloud computing can offer robustness and alleviate traffic congestion issues. The management layer can monitor traffic and respond to peaks or drops with the creation of new servers or the destruction of unnecessary ones. The management layer has the additional ability to be able to implement security monitoring and rules throughout the cloud. Figure 2 shows the basic diagram of this layout.

Figure 2.

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Cloud can worsen the damage on traditional frameworks for privacy that globalization has already started. For example, location of the data is critical from a legal point of view. But in the cloud, information might be in multiple places, might be managed by different entities and it may be difficult to know the geographic location and which specific servers or storage devices are being used. It is currently difficult to discover and meet compliance requirements, as existing global legislation is complex and includes export restrictions, data retention restrictions, sector- specific restrictions and legislation at state and/or national levels. Legal advice is required, transborder data flow restrictions need to be taken into account, and care must be taken to delete data and virtual storage devices when appropriate.

High security is one of the major obstacles for the adoption of computing as a utility as the sensitive applications and data are moved into the cloud data centers. This unique attributes, however, poses many novel tangible and intangible security challenges such as accessibility vulnerabilities, virtualization vulnerabilities, and web application vulnerabilities. These challenges relate to cloud server having physical control of data, relate to identity and credential management, relate to data verification, tempering, integrity, confidentiality, data loss and theft. To protect private and sensitive data that are processed in data centers, the cloud user needs to verify: