Google, True Ventures, and Resonant Invest $5 Million Into Duo Security

Posted Feb 28, 2012

Duo Security is an Ann Arbor, Michigan based company that has raised $5 million in funding from Google Ventures, True Ventures, and Resonant Venture Partners. True and Resonant previously invested $1 million into Duo. Duo Security is best known for developing its two-factor authentication technology, which requires users to authorize important online decisions separately through a webpage separately through a mobile device.

Duo Security CEO Dug Song said that the company’s solutions are relatively simple, but they provide a practical answer to small businesses and corporate technology companies that are concerned about web attacks.

“These days anything of any value that’s sitting behind a log-in can and will be attacked,” said Song in an interview with “We see ways to try to solve that problem at scale both for our small customers as well as our large customers.” Duo Security’s customers include the University of Michigan, Tumblr, and Toyota.

Currently Duo is based in the Tech Brewery startup business incubator in Ann Arbor, but Song believes that they are starting to outgrow its presence there. The company is currently weighing their options on how to handle their growth.

Duo Security was co-founded by chief technology officer Jon Oberheide. Oberheide recently finished his PhD in computer science from U of M.