Microsoft on Thursday announced that it has acquired PhoneFactor, provider of multifactor authentication technology delivered via a mobile device. The deal, terms of which were not disclosed, will enable Microsoft to provide its customers with stronger authentication for cloud- and application-based services, the companies said. PhoneFactor's tokenless authentication system already is compatible with widely used Microsoft offerings, including Active Directory, Outlook Web Access and Internet Information Systems. In a blog post, PhoneFactor CEO and co-founder Tim Sutton said the company "will continue to support existing customers in the same manner we do today and we remain open for business and ready to work with you..."