The effort is backed by Sun Microsystems and a number of hardware, software and consumer services companies such as United Air Lines, General Motors and American Express. It now has more than 95 members from private industry, non-profit organisations and government.
New members include Sprint, security and authentication technology maker Baltimore Technologies, network management software maker Oblix and Internet2, a consortium of university researchers, private industry and government agencies that are working to develop and deploy advanced network applications.
The Liberty Alliance released the first version of its specification in July based on the security standard Security Assertion Markup Language (SAML). Users would be able to use a single online identity to traverse Web sites or gain access to corporate applications and databases that support the Liberty Alliance specification.
The specification allows Web site operators to build in functions that allow users to "optin" to share their user name and password with other Liberty-enabled Web sites, as well as a "global logout" for signing off all participating Web sites in a single action.
Similar technology is available from Microsoft through its Passport authentication service, where users can use Passport member Web sites without having to re-enter a user name and password each time.
Microsoft and the Liberty Alliance have yet to synchronise their efforts, though Microsoft said that it would include support for SAML in future versions of its Windows operating system.
The next release of the specification is expected to allow users to store additional information, such as a credit card number, for online shopping.