TCG Drive Encryption Goes Mainstream

The Trusted Computing Group's newly released specifications for the management of hard drive encryption are now being adopted by a number of vendors -- Seagate arguably the most prominent, but also including Fujitsu, Toshiba, Hitachi, Wave Systems, CryptoMill, WinMagic, Secude, and McAfee.These specifications (PDF) focus on how the drives are managed by host-side applications, and should provide the dual benefit of increased performance with encrypted drives, driving a wider implementation of this security technology. What this enables is vastly lowered barriers to entry for related products because the standards allow hardware-encrypted drives from a wide variety of conforming vendors to be plug-compatible.

This, in turn, has the dual benefit of lowering costs through competitive standardization and increasing adoption of the related technology. The National Security Agency, which participated in this effort, has issued a letter of acceptance for one of the participating vendors, demonstrating that it's also behind this effort.

Standard Advantages Advantages to this TCG Hard Drive encryption approach include improved setup time, enhanced scalability, interoperability, increased security over keys, portability, and platform breadth. Let's take a look at each.

Setup Time: With this class of encryption product, data is encrypted from the time the drive is manufactured. Turning on the security is nearly instantaneous because the drive is already encrypted. With other forms of encryption, the drive must first become encrypted when the feature is turned on, requiring the encryption of the then-resident drive contents (which can be very time-consuming).

Scalability: For more traditional CPU-based solutions, when multiple drives are introduced, they will bottleneck once the capacity of the CPU and chipset is reached. With drive- based encryption, the restricting function is handled by the drive and scales up in performance with each drive added.

Interoperability: Chipsets vary greatly between processor vendors, and have since the late '90s. Processor/chipset-based approaches tend to tie the drives to the chipset and processor solution, and have difficulty moving between solutions (if at all) without performance impact. The TCG approach is plug-compatible across vendors, virtually eliminating this problem.

Key Security: With CPU/chipset solutions, the keys for each hard drive need to be managed by the host-side application. They are generally stored in memory so they can be made accessible to the CPU. This leaves the keys vulnerable to kernel-level attacks and others, like the Princeton cold-boot attack. With the TCG method, the keys are sent to the hard drive during the preboot -- typically using a security-hardened application. This makes them more difficult to compromise.

Portability: Drives based on the TCG specification can be moved between PCs because, unlike other methods, there is no system-level dependency. This is because the encryption engine is inside the drive and not dependent on the unique aspects of any one PC configuration.

RAID Performance: Chipset/CPU configurations are particularly painful on servers or multiple-drive desktops because they shift the encryption load to the processor and chipset, which generally is already running at a high-level load in such a configuration. That typically leads to a significant bottleneck.

Wrapping Up The TCG's new specifications, as well as drives from the vendors now supporting them, have been needed for some time and address a number of high-performance, interoperability, and security concerns. This change represents a significant improvement in an industry (storage) that doesn't have many of them in any given year.

-- Rob Enderle is president and founder of Enderle Group. Special to Dark Reading.