As one of the hottest trends going in the information/computing world, how do the requirements for cloud security relate to the security concerns that enterprises have been addressing prior to the uptick in cloud computing? While the cloud is a relatively new area for concern, improved security has been a hot button for organizations of all size for well over a decade.

The cloud continues to evolve with various services and models including externally hosted public cloud services such as Amazon, independently hosted cloud services by an enterprise or third party that are either outside the firewall or inside the firewall (private cloud services), and a hybrid of private/internal and public/external models. On the surface, the different models might appear to have different privacy, access control and data protection issues. However, compliance issues and business data leakage out of any of these clouds pose problems for an organization similar to ones that existed prior to working in the cloud.

No matter which cloud services or model is pursued, security improvements should be among the criteria on the "must have" list. Issues to consider include: hardware versus software-based security, hardware activation, known users, known machines, accessing both data and application services, data protection and compliance, and protecting the service provider's agreement for controlled user access. For data leakage and access control, authorization to access information from the cloud, whether it's an application or an application with data, requires a trusted endpoint to ensure strong authentication and knowledge of who is accessing the cloud service and the data hosted by the cloud service. In fact, a trusted endpoint is part of the solution for addressing all of the issues. One solution involves implementing the Trusted Platform Module (TPM), a widely available security chip that already resides in most business PCs. This standard-based hardware component provides stronger security than software-only approaches that can be stolen, hacked, impersonated or worse, causing security breaches and business disruption.

Hardware-Based Trust
Developed by the Trusted Computing Group (TCG), the TPM is a standard for providing a hardware-based root of trust for computing and other systems. Unlike other hardware token security tools that are available in USB, key fob, and smart card type products, the standards-based TPM is typically an application-specific integrated (ASIC) available from multiple sources to ensure a highly competitive and readily available component installed in the computer when it was manufactured. TPM capability also can be integrated into chipsets, Ethernet controllers, and the like. To date, it has been is estimated that 200-300 million TPMs have shipped in enterprise PCs based on these standards.

The open standards-based approach provides a low-cost, flexible solution from multiple sources with a higher adoption rate and extensive support from over 100 technology companies in the industry across the globe. International governments have already adopted or plan to adopt the TPM as the standard for authentication. If these governments pursue cloud services, they will not proceed without a similar strong authentication methodology - and they will not implement proprietary technology.

Although inside the computer, the TPM needs to be activated by the user to enable its ability to improve security. Once the TPM is activated, users can more securely store and manage keys and passwords as well as easily encrypt files, folders and email. The TPM allows multi-factor authentication to be based on hardware vs. the simple password in software. For multi-factor authentication requirements, the TPM complements fingerprint readers, PKI, certificates and smart cards.

Dual-Level Identification & Authentication
As a hardware item inside the computer, the TPM allows the identification of the machine as well as the user.

This elevates the sign-on process to two-factor or dual-level authentication: the user through their passwords and the second through the machine itself or the machine's authentication to a service. The approach provides a significant increase in security, especially when compared to single-factor software-only approaches.

With its secure storage for a credential or critical piece of information, the TPM also provides the ability for a multi-use module where multiple users employ the machine's TPM for machine authentication and each user authenticates to the machine. A user could have a single sign-on to different services but would still have to authenticate to the machine. Once the user has authenticated to the machine, the machine can release credentials.

The layers of authentication, where the machine is known by the cloud and the machine has a relationship with the user, significantly enhance cloud security. This process provides a chain of trust for machine-to-machine connectivity so that only known machines and known users obtain access to applications and data. Implementing this dual-level authentication solves one of the most frequently discussed cloud issues - specifically knowing the users and machines that are connected to the cloud service.

Integrating Solutions
The TPM's hardware-based security can easily integrate with software security identification (ID) standards for federated ID management such as OpenID, Security Assertion Markup Language (SAML), WS (Web Services) - Federation and others. For example, OpenID is an industry standard protocol for communication or authentication at the service level. Over 20,000 service providers support OpenID as a software token. Figure 1 shows the process for cloud access based on the two-level authentication and an identity service that uses OpenID.

Figure 1: Improved cloud security requires a hardware-based TPM token to ensure machine integrity.
Source: id.wave.com.

A cloud service can use the TPM binding an OpenID certificate to the TPM for strong machine authentication to their service. This provides not only the identity of the client but could provide a health measure as well. The service could measure the health of the client, verify a relationship, and then provide the appropriate access. This also allows multiple users per client because the machine has a relationship with the service and multiple users have relationships with the machine. The process extends the security approach across different use models.

SAML, WS-Federation and other software identification standards can be implemented in a similar manner for establishing a known identity for cloud access. The essential element for sharing an identity is a trustworthy endpoint. In all of these cases, the TPM provides the base level, the foundation of trust.

Summary
The hardware-based security model that has been described supports cloud-based private/internal, public/external and hybrid combinations of both as well as traditional IT managed networks. This allows a reuse of the security technology for minimizing costs, including the reuse of corporate client policies. The alternative is continuing on the same path of software-only authentication. However, software in the computer can be hacked, impersonated, stolen, or victimized by the malicious software it is attempting to stop. This is the same model that is broken inside the enterprise today.

Once hardware-based access is implemented for machine authentication, it enables the use of other industry standards-based tools for self-encrypting drives (SEDs) and trusted network connect (TNC). These added tools can address the data leakage problem that may result from storing the data accessed from the cloud on a user's client. The journey towards higher cloud security begins with the first step of establishing a foundation by implementing the hardware-based security of the TPM.