Next-Generation Secure Computing Base

The Next-Generation Secure Computing Base (NGSCB; codenamed Palladium and also known as Trusted Windows) is a software architecture designed by Microsoft which claimed to provide users of the Windows operating system with better privacy, security, and system integrity. It was an initiative to implement Trusted Computing concepts to Windows. NGSCB was the result of years of research and development within Microsoft to create a secure computing solution that equaled the security of closed platforms such as set-top boxes while simultaneously preserving the backward compatibility, flexibility, and openness of the Windows operating system. Microsoft's primary stated objective with NGSCB was to "protect software from software."

Part of the Trustworthy Computing initiative when unveiled in 2002, NGSCB was to be integrated with Windows Vista, then known as "Longhorn." NGSCB relied on hardware designed by the Trusted Computing Group to produce a parallel operation environment hosted by a new hypervisor (referred to as a sort of kernel in documentation) called the "Nexus" that existed alongside Windows and provided new applications with features such as hardware-based process isolation, data encryption based on integrity measurements, authentication of a local or remote machine or software configuration, and encrypted paths for user authentication and graphics output. NGSCB would facilitate the creation and distribution of digital rights management (DRM) policies pertaining the use of information.

NGSCB was subject to much controversy during its development, with critics contending that it would impose restrictions on users, enforce vendor lock-in, prevent running open-source software, and undermine fair use rights. It was first demonstrated by Microsoft at WinHEC 2003 before undergoing a revision in 2004 that would enable earlier applications to benefit from its functionality. Reports indicated in 2005 that Microsoft would change its plans with NGSCB so that it could ship Windows Vista by its self-imposed deadline year, 2006; instead, Microsoft would ship only part of the architecture, BitLocker, which can optionally use the Trusted Platform Module to validate the integrity of boot and system files prior to operating system startup. Development of NGSCB spanned approximately a decade before its cancellation, the lengthiest development period of a major feature intended for Windows Vista.

NGSCB differed from technologies Microsoft billed as "pillars of Windows Vista"—Windows Presentation Foundation, Windows Communication Foundation, and WinFS—during its development in that it was not built with the .NET Framework and did not focus on managed code software development.