Positive Networks, a provider of hosted VPN services, is using Interop to promote a two-factor, telephone (land-line or cell)-based authentication system for users looking to access corporate applications. The company will look to hook customers with the authentication technology -- it's free -- then sell a series of add-on services.The Positive product, known as PhoneFactor, requires a corporate customer to download a Windows-based software agent from the Web, and install it on a Citrix or Exchange Server. When attempting to access an application, a user enters their user name and password, then the PhoneFactor agent verifies their identity and calls the user on a predetermined land line or cell phone, authorizing the session. The phone call is launched from a Positive Networks point of presence - the same points of presence hosting its VPN service.

The company is pitching PhoneFactor as a simple, inexpensive alternative to security tokens and the IT work required to install and maintain them.

It sees users that deploy the software potentially needing fee-based services such as consulting on deployment, integration to existing directory systems, reporting and more.

You can't beat the ROI.