Microsoft, EMC and Cisco Systems on Tuesday jointly unveiled plans to build a system for sharing sensitive government data called the Secure Information Sharing Architecture (SISA) that will let various government agencies and their vendors securely share sensitive information.

The SISA Alliance, which also includes three smaller vendors, will create a set of common IT architectures that grant only authorized personnel and communities the ability to access, store and exchange protected data within secure virtualized networks, according to officials at Hopkinton, Mass.-based EMC.

The goal of the SISA Alliance, according to officials of the sponsoring firms, is to remove silos of data management and data protection that have been commonly instituted within specific government entities.

Cisco will lend its network protection and secure virtualized network links capabilities, EMC will provide its networked storage systems and information life cycle management tools, and Microsoft will add its identity management software and its expertise in client systems and operating systems, the executives said.

The other vendors include Liquid Machines, which will provide content protection expertise, Swan Island Networks, which specializes in trusted computing environments, and Titus Labs, a provider of e-mail and document classification tools.

The companies agreed to jointly unveil technology developed under the program, and to require that all distributors of the technology be certified under a SISA Alliance program. The program will require such distributors to complete a SISA training program, thereby validating their ability to offer system integration or professional services expertise to support SISA implementation, officials said.

The companies didn't provide a timetable or an estimate of the system's cost, and government representatives weren't available for comment early Tuesday.