PhoneFactor, now a Microsoft Company | 282 followers on LinkedIn. PhoneFactor pioneered the use of phone-based authentication for enterprises when it launched its innovative cloud service in 2007. The company joined the Microsoft family in 2012, and the PhoneFactor service is now available as Windows Azure Multi-Factor Authentication. In addition to securing on-premises applications and identities, the service now also works with cloud applications like Office 365 that use Windows Azure Active Directory.