Security of virtualization solutions- Present and future

Cloud computing seems to be the major recent change in the way IT resources and services are offered, used and managed. Opening up infrastructures and services to third parties, the novelty lies in seeing them as provided and used on demand.

The associated benefits are numerous: reduced costs, improved scalability... This "self-service" vision is based on sharing a set of computing, communication and storage resources. All securely accessible via broadband networks, rapidly provisioned and released as needed. This flexibility is underpinned by virtualization: resources and services are separated from the infrastructure in the form of virtual machines (VMs).

This new context raises many questions about resource protection, making security one of the main obstacles to cloud adoption. For example:

• on isolation, as a cloud infrastructure is shared between several tenants with often distinct security objectives;

• on the disappearance of organizational boundaries, making it difficult to guarantee perimeter security;

• on the loss of control over applications and data that run, are transmitted, or are stored in insecure environments;

• on new vulnerabilities linked to virtualization.

Of these questions, the last is probably the least understood:

• what are the threats to a virtualized infrastructure?

• what is a hypervisor and what virtualization techniques are available?

• what mechanisms are available today to protect against these threats?

• What is the current state of research, and what prospects does it offer for improving the safety of these systems?

This article aims to provide some answers to some of these questions, on the influence of virtualization on security.

After a brief overview of the various cloud models (§ 1 ), we present the principles, approaches and solutions for system virtualization (§