Ann Arbor startup Duo Security lands $5 million from investment group including Google

Google Ventures, Silicon Valley-based True Ventures and Ann Arbor-based Resonant Venture Partners invested in Duo, officials announced today. True Ventures and Resonant were previous backers of Duo, which raised $1 million in 2010.

The investment gives the company additional capital to grow and represents a significant vote of confidence in its "two-factor authentication" technology, which requires users to authorize important online decisions separately through a web page and a mobile device.

Dug Song, CEO of Duo Security, said the company's relatively simple but secure solution provides a practical answer to corporate technologists and small businesses that are concerned about web attacks.

"These days anything of any value that's sitting behind a log-in can and will be attacked," Song said in an interview. "We see ways to try to solve that problem at scale both for our small customers as well as our large customers."

He added: "You've got teenagers turning major corporations inside out and violating consumers' privacy on a scale that's never been seen before. And the market needs a solution that can address it."

Duo's customers include the University of Michigan, Toyota and social media site Tumblr.

"We have customers that have hundreds of millions of users," said Song, who added that attracting interest from Google is "fantastic for the company."

Karim Faris, a Google Ventures partner, said in a statement that Duo "is committed to democratizing strong authentication and bringing this previously ‘enterprise-only’ level of security to every Internet user."

“Proper identity assurance and mobile security are critical for the growth of meaningful online services,” said Faris, whose organization can invest about $200 million annually.

Song said Duo has "outgrown" its presence at the Tech Brewery on Jones Drive, a vibrant startup business incubator where entrepreneurs can rent space by the desk. He said the company is weighing its options on how to handle its growth and whether that means moving to a new office. He declined to say how many employees the company has.

"We're growing methodically," Song said. "The capital is going toward the growth, making sure people handle that and support that adequately."

Song and Duo's chief technology officer, Jon Oberheide, who recently completed his PhD in computer science from U-M, co-founded Duo Security.

Song, a former chief security architect at Ann Arbor-based U-M success story Arbor Networks, is an active proponent of Ann Arbor's technology community and a community activist who helped successfully push for a new skate park to be constructed at the city's Veterans Memorial Park.

Song said the company's investment shows that local software companies can secure outside investment.

"Clearly there is an opportunity for more software startups to come out of Ann Arbor, and that's one of things that we are going to, in a very hands-on way, support," he said.

Contact AnnArbor.com's Nathan Bomey at (734) 623-2587 or nathanbomey@annarbor.com. You can also follow him on Twitter or subscribe to AnnArbor.com's newsletters.