To help secure organizations by providing visibility into what they have exposed on the Internet.

It’s no longer sufficient for organizations to only protect servers and devices on managed, corporate networks. In order to get a comprehensive view of their public-facing attack surface, organizations must adopt an Internet-wide perspective and gain visibility into both known and unknown infrastructure, including vulnerable, unpatched servers and devices.

Founded by Security Researchers

The foundational technology behind Censys was designed by researchers at the University of Michigan. This team also created the ZMap Scanner, which helped popularize Internet-wide scanning.

Their original goal was to provide researchers with a way to measure if Internet security was actually improving. To accomplish this, they needed to track security vulnerabilities on every reachable server and device on the Internet, and collect as much data as possible about those hosts. The result was a searchable map of the Internet, which became a powerful tool for security researchers.

This map also proved valuable to the broader information security community. Corporate security teams and consultants were also using it to identify business infrastructure and to prevent unnecessary exposure on the Internet.

In 2017, the founding research team partnered with two seasoned product leaders to build a company with the mission of helping organizations secure themselves through visibility and real-time data.

Company Leadership

Our founding team combines the world's leading experts on Internet-wide security scanning with experienced business leaders with a history of successful security startups.

Brian Kelly

Brian Kelly

Chief Executive Officer

Brian has been building startup software products and companies for over a decade. Most notably, he’s led product teams at Duo Security (acquired by Cisco), TrustBearer Labs (acquired by Symantec), and Nutshell.

David Concoran

David Corcoran

Chief Operating Officer

Dave is a serial software startup entrepreneur, angel investor, and recognized expert in the identity and authentication space. He was CEO and founder of TrustBearer Labs (acquired by Symantec).

Zakir Durumeric

Zakir Durumeric

Chief Technologist

Zakir is an Assistant Professor of Computer Science at Stanford University. He helped pioneer Internet-wide scanning as one of the creators of ZMap and Censys.

David Adrian

David Adrian

Principal Engineer

As a Ph.D. candidate at Michigan, David was the lead developer of the Censys research project and devised measurement-based approaches to discover and correct security problems.

Alex Halderman

J. Alex Halderman

Chief Scientist

Alex is a Professor of Computer Science at Michigan. He helped create ZMap, discover the Cold Boot attack and the TLS Logjam and DROWN vulnerabilities, and co-founded Let's Encrypt.

Advisors & Investors

HD Moore

HD Moore

Founder Metasploit

HD is a security researcher and consultant well known for creating Metasploit. HD previously led the Project Sonar project at Rapid7.

Dug Song

Dug Song

CEO of Duo Security

Dug is a renowned security researcher and industry leader. Prior to launching Duo (acquired by Cisco), he spent seven years as Chief Security Architect at Arbor Networks.

Greylock Partners Logo

Greylock Partners


Greylock Partners backs entrepreneurs who are building disruptive, market-transforming consumer and enterprise software companies.

GV logo



GV provides venture capital funding to bold new companies. In the fields of life science, healthcare, artificial intelligence, robotics, transportation, cyber security, and agriculture.

Mapping the Internet

Censys uses Internet scan data to give organizations the visibility they need to defend against attacks and improve their overall security hygiene