Microsoft has further watered down the Next Generation Secure Computing Base (NGSCB) technology that will ship with its forthcoming Longhorn operating system.

Many systems which Microsoft claims are "Longhorn ready" will not be able to support the security technology, vnunet.com has learned, and only part of the original security vision will be ready in time for the operating system's launch.

"With the Longhorn launch we are delivering the first part of NGSCB: Secure Startup," Jim Allchin, Microsoft's group vice president for platforms, told vnunet.com at the Windows Hardware Engineering Conference (WinHEC) in Seattle. "Not all of the compartmentisation technology will be available. The main thing is Secure Startup."

Secure Startup protects users against offline attacks, blocking access to the computer if the content of the hard drive is compromised. This prevents a laptop thief from booting up the system from a floppy disk to circumvent security features or swapping out the hard drive.

Microsoft unveiled NGSCB, formerly codenamed Palladium, in 2002, and published a beta in October 2003. The security technology has since undergone several changes.

The company originally planned for the technology to deliver a rigid level of security, creating physical separations between applications.

It was designed to prevent a virus from entering the operating system through the browser and making its way to the email application to further spread itself.

The technology used a newly developed software component called a 'nexus' to shield applications from each other and the operating system. A chip, the Trusted Platform Module (TPM), is used to encrypt data streams between the operating system and applications.

The original plans required users to purchase new hardware and software. Last year at WinHEC Microsoft reversed that decision.

Instead of shielding individual applications, the technology would create secure compartments for elements such as the operating system, computing tasks and administration and management.

Although initially intended to ship as part of Longhorn, the secure compartments have now been pulled from the platform and will be released later.

Microsoft has kept quiet about the changes in the program. The company cancelled a session at WinHEC about technology titled How to build NGSCB-enabled systems, replacing it with a session called How to build in support for secure startup.

A spokeswoman for Microsoft claimed that the session title was changed because the new title better reflected the revised content.

In addition to NGSCB features being pulled, many systems will not be able to support any of the new technology by the time Longhorn comes out.

The security platform depends on a TPM chip being present in the system. The chip is an industry standard governed by the Trusted Computing Group, a non-profit organisation which develops security standards.

Meanwhile, Microsoft has launched a logo programme at WinHEC dubbed 'Ready PC', indicating that a system is capable of running Longhorn. The logo tells users looking to buy a computer prior to the Longhorn launch whether a new system is able to switch to the upcoming operating system.

Qualifying systems require at least 512MB of memory and a current mid- to high-end processor. But the programme does not demand a TPM chip to be present, Allchin told vnunet.com.

Manuel Novoa, a distinguished technologist and security architect at HP's Personal Systems Group, told vnunet.com that the TPM is an "if implemented" requirement. This means that Longhorn will support the technology when available, but that the chip is not required.

Although the 'Ready PC' logo tells users that they are buying a system that runs on Longhorn, they may unwittingly buy a computer that will not support NGSCB.

Novoa called the version of NGSCB that users will get in Longhorn as "NGSCB with a delay".

"Rather than deliver nothing, Microsoft is saying: 'Let's do what we can deliver.' [Microsoft] had to cut functionality to meet a launch date," said Novoa. He expects the technology to be ready by 2007 or 2008.

A delay in the development of Microsoft's virtualisation technology is to blame for the changes in NGSCB, Rob Enderle, a principal analyst with the Enderle Group, told vnunet.com.

Virtualisation technology is required to create the secured compartments. The fact that the TPM is not a requirement of the Ready PC programme is in part a result of resistance from manufacturers and end users, according to the analyst.

"A lot of people are nervous about the TPM," said Enderle. "They fear that the TPM is a tool for the US government to spy on users worldwide, or that the chip can be used to set and enforce digital rights management policies."

Microsoft had wanted the TPM as a requirement for the programme, but was forced to back down. "Do you implement a technology that a large chunk of the world doesn't want?" asked Enderle.