Vint Cerf was in his early thirties, teaching at Stanford, when he and Bob Kahn designed the protocol suite that now runs the internet. The Defense Department’s TCP/IP, built to connect separate packet networks, came out of Cerf’s research on interconnection protocols between 1972 and 1976.
Cerf was born in New Haven, Connecticut, on June 23, 1943. He studied mathematics at Stanford, spent two years at IBM supporting QUIKTRAN, then left for UCLA, where he earned a master’s degree in 1970 and a PhD in 1972. At UCLA he worked in Leonard Kleinrock’s packet networking group, which linked the first two nodes of the ARPANET. That is where he met Kahn, who was working on the ARPANET’s architecture.
The first TCP specification, written with Yogen Dalal and Carl Sunshine, was published as RFC 675 in December 1974.
From DARPA to MCI
From 1973 to 1982 Cerf worked at DARPA, the Defense Department’s research agency. He funded groups building TCP/IP, packet radio, packet satellite and packet security technology. Those efforts grew out of military needs.
He then moved into business. At MCI Digital Information Services he led the engineering of MCI Mail, the first commercial email service connected to the internet, in 1989. In 1986 he joined Kahn at the Corporation for National Research Initiatives, and in 1992 the two, with others, founded the Internet Society, where Cerf served as first president. He rejoined MCI in 1994 as senior vice president of technology strategy.
MCI also brought him criticism. The company supplied IP addresses to Send-Safe.com, a vendor of spam software that used a botnet, and refused to cut it off.
Cerf worked at Google from October 2005 to July 2026, as a vice president and Chief Internet Evangelist. He joined ICANN’s board in 1999 and chaired it from November 2000 until he left in November 2007. In a February 2006 Senate hearing on net neutrality he said nearly half of US consumers had no meaningful choice of broadband provider.
Honors, and a network for space
In December 1997 President Bill Clinton presented Cerf and Kahn with the National Medal of Technology. Cerf has also received the Turing Award, the Presidential Medal of Freedom and the Marconi Prize, and he belongs to the National Academy of Engineering.
Cerf and his wife Sigrid both have hearing loss. He joined the board of trustees of Gallaudet University in 1997.
He is also working on an Interplanetary Internet with NASA’s Jet Propulsion Laboratory and other NASA labs, a standard meant to tolerate the variable delay and disruption of signals between planets. In June 2016 that work put delay-tolerant networking on the International Space Station.
Since at least 2015 he has warned about digital obsolescence, the risk of losing historic information because the software and hardware needed to read it disappear. He calls the possible result a digital “Dark Age.”
