In the fall of 2010, Trusted Computing Group announced the Trusted Multi-tenant Infrastructure (TMI) Work Group to address cloud computing security and the role of trust in that security. Last week, the work group released the first in a series of use cases (http://www.trustedcomputinggroup.org/developers/trusted_multitenant_infr...) and plans to deliver a reference framework later in 2011. With so much hype and confusion around the topic of cloud computing, we thought it might be useful to ask the co-chairs - Michael Donovan, HP, and Erik Visnyak, BAE Systems - of the TMI Work Group a few questions about their group's efforts.

Q. What role does Trusted Computing Group have in helping secure cloud services?

Michael Donovan & Erik Visnyak: Securing the cloud is a multidisciplinary challenge, as cloud computing can be thought of as a different way to deliver and use all of the same types of information technology we use today. The TCG was established to define standards and practices for building trusted infrastructure that will consistently behave in specific ways, and those behaviors will be enforced by hardware and software when the owner of those systems enables these technologies. The ability of trusted infrastructures to provide integrity measurements and attest to their state provides a key foundation for enabling trust in infrastructure platforms in the cloud, where the consumer does not have direct physical access to those resources. The ability to design, build and consume services delivered from a trustworthy infrastructure where providers and consumers of services can measure and attest to the configuration, state and behavior of platforms is the value of the TCG standards within the cloud ecosystem.

Q. Your work group has a long name. What does it mean?

Donovan & Visnyak: TMI stands for Trusted Multi-Tenant Infrastructure.  We wanted to select a name that properly represents delivering trusted operations and configuration/state validation to a multi-tenant infrastructure such as Cloud Computing.

Trust is the degree to which one party will rely on the assertions or information provided by another. Without the ability for an infrastructure consumer to rely on the information and services from a provider, there is likely to be little market for outsourcing of IT platforms and services. Establishing a trusted context for the providers and consumers of shared infrastructure is a key component of the reference framework under development by TMI.

Multi-tenancy is the ability for multiple unrelated consumers to share infrastructure from a common provider. If consumers were not able to share infrastructure within reasonable constraints, the cost of outsourced services would not be competitive with traditional models. This ability to provision as much or as little of a resource as a consumer needs at a fair price is at the heart of cloud computing.

Infrastructure defines the scope of work for the TMI work group. While the principles and reference model may have applicability to other parts of the cloud ecosystem, the TMI focus is clearly focused on developing reference models and best practices for design, build and consume trusted multi-tenant infrastructure platforms.

Q. How is what you are doing different from what CSA and other orgs have done or are doing?

Donovan & Visnyak: Many traditional IT standards bodies are working to apply their existent standards efforts to the cloud computing ecosystem. Some, such as DMTF, are focused on systems management and definition of physical and virtual resources, such as the Open Virtual Machine (OVF) definition for virtual machines. Newly formed organizations, such as CSA, focus on mitigating threats and risks within cloud computing by proposing best practices and link to specific security requirements for public and private sectors. As cloud potentially encompasses much of the existing IT landscape, each of these organizations has a valid role to play.

The TCG TMI work group is focused on standards-based approaches to trusted infrastructure. We intend to iteratively publish a library of use cases, deployment patterns, best practices and compliance testing to support the ability of infrastructure providers and consumers to make effective use of shared multitenant infrastructures.

TMI is identifying how standards can be used to implement trusted infrastructures as well as identifying any potential gaps. TMI will provide implementation guidance to both consumers and providers as to how standards address concerns within cloud computing and how they may be leveraged to create a trusted shared infrastructure environment.

Q. Your use cases mention "trust" a number of times. What exactly does "trust" mean for multi-tenant infrastructure?

Donovan & Visnyak: Trust is the degree to which one party will rely on the assertions or information provided by another. Without the ability for an infrastructure consumer to rely on the information and services from a provider, there is likely to be little market for outsourcing of IT platforms and services. Establishing a trusted context for the providers and consumers of shared infrastructure is a key component of the reference framework under development by TMI.

Trust enables the ability to apply policy and to guarantee that access controls within policies are adhered to in order to supply reliable logical isolation, guaranteed compliance, and continuous policy compliance monitoring within a multi-tenant environment. This allows the various consumers to trust that providers are meeting their concerns and housing their resources in a trusted fashion.

Q. Do you see other TCG specifications such as the TPM or TNC playing a role in a "trusted" cloud? If we have a bunch of PCs with TPMs, for example, can they be used in a multi-tenant infrastructure?

Donovan & Visnyak: The existing TCG standards provide a critical set of foundational services for establishing trust, exchanging information in a trusted context, enforcing policy, binding together and verifying the trusted state of infrastructure components. Without these core standards, it is unlikely we would be able to achieve the level of trust and compliance we see as critical to the ability of consumers to trust and effectively use cloud computing for core business functions.

TPM provides the ability to attest to a secure state that moves beyond software into the hardware of the infrastructure providing another level of security to assure that integrity and confidentiality of resources within the TMI are maintained.  TNC delivers monitoring of the secure state of TMI resources and utilizes policy enforcement to monitor data exchanges between resources within the TMI to ensure policy compliance.

The TMI working group intends to work with these key TCG standards working groups as well as those from other standards bodies to ensure that the business and mission goals of cloud consumers can be met in a secure trusted context.

Q. Why are you publishing use cases and what are they for?

Donovan & Visnyak: We are utilizing these use cases to describe the context and relationships between components in a trusted infrastructure. The first set of use cases are very narrow in scope and cover some of the key relationships necessary to establish and manage a trusted multi-tenant, multi-provider environment. Later use cases and scenarios will expand on this work and include scenarios putting these lower level use cases into business context.

The use cases are utilized to derive the elements of the reference framework and other downstream specifications. They define the parties, interface interactions and relationships between them to assist in scoping and validating the usage patterns and requirements included in the reference framework. The use cases allow the TMI to begin identifying various security requirements necessary for a TMI and begin the process of identifying standards within industry that map directly to use cases and implementation patterns.

Q. What else will you be doing?

Donovan & Visnyak: The next things you should see from TMI are aligned to the following path (in addition to presentations and white papers):

• Use cases (initial set delivered)
• Reference framework (high-level requirements and usage pattern library derived from initial use cases)
  • Patterns describe re-usable approaches to meeting the requirements derived from the use cases
  • Patterns are aligned to implementation standards for evaluation of tools and services
• Implementation guidance (core guidance on how to use the patterns to build a trusted multi-tenant infrastructure)
  • Includes variants based upon general levels of trust, separation and security
• Framework compliance test suite (guidance and (possibly) test harnesses for verification of compliance to TMI implementation patterns and standards)
• Specification development strategy (if gaps are identified in the standards ecosystem necessary to achieve TMI compliance, a plan to address with the relevant bodies)
• Industry profiles (implementation guidance, test suites and standards alignment targeted at specific industry solutions i.e. defense, PCI-DSS, HIPAA and others)

We plan to continue iterative development of our reference implementation patterns that are repeatable interactions and behaviors that can be implemented by utilizing industry standards that allow for TMI.  As patterns are developed we will engage appropriate standards bodies to see how the technology can apply to the implementation standards as well as its corresponding use cases.

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Updates to the TMI Work Group will be available online at TCG's website, www.trustedcomputinggroup.org.