Launched in September by Sun Microsystems and various IT vendors, the Liberty Alliance is working to build a common technology that enables Web users to enter only once the personal information they need to access password-protected sites. The Liberty Alliance is also aiming to make the service decentralised so that no single company can have total control of it.
AOL will become the 34th member of the coalition, paving the way for its subscribers - about 32 million users - to eventually have access to the Liberty Alliance service.
The company's participation in the technology group adds a new element to the heated competition among rival authentication services as they become more integral to accessing service on the Internet, said Chris Le Tocq, an analyst with Guernsey Research.
"From an authentication standpoint, the largest group of users out there is AOL," Le Tocq said.
AOL's admission into the group will encourage competition and consumer choice while protecting privacy and security, AOL said.
The company has urged Microsoft to take part in this system as well, according to an AOL spokesman. "We believe that if Microsoft chooses to do so it would be a strong indication that it was moving away from its efforts to control this new space," he said.
Microsoft, AOL and other major Web companies are banking on single-sign-on technology to enable wide adoption of new services and communications options on the Internet.
Competitors have raised concerns over Microsoft's Passport system, the biggest rival to the Liberty Alliance, arguing that one company should not control authentication on the Internet. But technical experts have also voiced opposition to single-sign-on services in general because they believe the security technology to be weak.
AOL already offers its users two authentication services. The first, called Screen Name Service, lets users sign on to AOL's Internet services and partner sites without re-entering a password. The second, an electronic wallet service called QuickCheckout, allows users to make purchases online at participating e-commerce Web sites. AOL also said it would continue developing a new authentication service, dubbed "Magic Carpet." The AOL authentication services will be interoperable with the Liberty Alliance system.
The technical details regarding how all the Liberty Alliance members will make their authentication systems work with each other have yet to be worked out.