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Robert E. Kahn
Born	December 23, 1938 (1938-12-23) (age 71)
Nationality	USA
Fields	Computer Science
Institutions	DARPA Corporation for National Research Initiatives
Alma mater	City College of New York (B.E.E.), Princeton University (M.A., Ph.D.)
Known for	TCP/IP
Notable awards	Presidential Medal of Freedom Turing Award

Robert Elliot Kahn (born December 23, 1938) is an engineer who, along with Vinton G. Cerf, invented the Transmission Control Protocol (TCP) and the Internet Protocol (IP), the technologies used to transmit information on the Internet.

Career

After receiving a B.E.E. degree from the City College of New York in 1960, Kahn earned M.A. and Ph.D. degrees from Princeton University in 1962 and 1964 respectively.

In fall 1972, he demonstrated the ARPANET by connecting 20 different computers at the International Computer Communication Conference, "the watershed event that made people suddenly realize that packet switching was a real technology."^[1] He then moved moved to ARPA (now known as DARPA) and helped develop the TCP/IP protocols for connecting diverse computer networks. After he became Director of DARPA's Information Processing Techniques Office (IPTO), he started the United States government's billion dollar Strategic Computing Initiative, the largest computer research and development program ever undertaken by the U.S. federal government.

After thirteen years with DARPA, he left to found the Corporation for National Research Initiatives (CNRI) in 1986, and as of 2009 is the Chairman, CEO and President.^[2] CNRI is a nonprofit organization which is intended to provide leadership and funding for research and development of the National Information Infrastructure.

The Internet

While working on a satellite packet network project, he came up with the initial ideas for what later became the Transmission Control Protocol (TCP), which was intended as a replacement for an earlier network protocol, NCP, used in the ARPANET. While working on this, he played a major role in forming the basis of open-architecture networking, which would allow computers and networks all over the world to communicate with each other, regardless of what hardware or software the computers on each network used. To reach this goal, TCP was designed to have the following features:

• Small sub-sections of the whole network would be able to talk to each other through a specialized computer that only forwarded packets (first called a gateway, and now called a router).

• No portion of the network would be the single point of failure, or would be able to control the whole network.

• Each piece of information sent through the network would be given a sequence number, to ensure that they were dealt with in the right order at the destination computer, and to detect the loss of any of them.

• A computer which sent information to another computer would know that it was successfully received when the destination computer sent back a special packet, called an acknowledgement (ACK), for that particular piece of information.

• If information sent from one computer to another was lost, the information would be retransmitted, after the loss was detected by a timeout, which would recognize that the expected acknowledgement had not been received.

• Each piece of information sent through the network would be accompanied by a checksum, calculated by the original sender, and checked by the ultimate receiver, to ensure that it was not damaged in any way en route.

Vint Cerf joined him on the project in the spring of 1973, and together they completed an early version of TCP. Later, it was separated into two separate layers, with the more basic functions being moved to the Internet Protocol (IP). The two together are usually referred together as TCP/IP, and are the basis for the modern Internet.

Recognition

He was awarded the Sigcomm Award in 1993 for "for visionary technical contributions and leadership in the development of information systems technology", and shared the 2004 Turing Award with Vint Cerf, for "pioneering work on internetworking, including .. the Internet's basic communications protocols .. and for inspired leadership in networking."

Vint Cerf and Kahn being awarded the Presidential Medal Of Freedom by Former President Bush

He is a recipient of the AFIPS Harry Goode Memorial Award, the Marconi Award, the ACM SIGCOMM Award, the President's Award from ACM, the IEEE Koji Kobayashi Computer and Communications Award, the IEEE Alexander Graham Bell Medal, the IEEE Third Millennium Medal, the ACM Software Systems Award, the Computerworld/Smithsonian Award, the ASIS Special Award and the Public Service Award from the Computing Research Board. He has twice received the Secretary of Defense Civilian Service Award. He is a recipient of the 1997 National Medal of Technology, the 2001 Charles Stark Draper Prize from the National Academy of Engineering, the 2002 Prince of Asturias Award, and the 2004 A. M. Turing Award from the Association for Computing Machinery. Dr. Kahn received the 2003 Digital ID World award for the Digital Object Architecture as a significant contribution (technology, policy or social) to the digital identity industry. In 2005 he was awarded the Townsend Harris Medal from the Alumni Association of the City College of New York, the Presidential Medal of Freedom, and the C & C Prize in Tokyo, Japan. He was inducted into the National Inventors Hall of Fame in May 2006. He was awarded the 2008 Japan Prize for his work in "Information Communication Theory and Technology" (together with Vinton Cerf).

• In 2001 he was inducted as a Fellow of the Association for Computing Machinery.

• Robert Kahn and Vinton Cerf were each inducted as an Honorary Fellow of the Society for Technical Communication (STC) in May 2006.

Dr. Kahn has received honorary degrees from Princeton University, University of Pavia, ETH Zurich, University of Maryland, George Mason University, the University of Central Florida and the University of Pisa, and an honorary fellowship from University College, London.

Articles

• Vinton Cerf & Bob Kahn, Al Gore and the Internet, 2000-09-28 [1]

See also

• Paul Baran co-inventor of packet-switched networks with Donald Davies

Notes

DBLP Listing

External links

• Biography of Robert E. Kahn on the Corporation for National Research Initiatives' website.
• Biography of Kahn from IEEE
• Oral history interview with Robert E. Kahn, Charles Babbage Institute, University of Minnesota, Minneapolis. Focuses on Kahn's role in the development of computer networking from 1967 through the early 1980s. Beginning with his work at Bolt Beranek and Newman (BBN), Kahn discusses his involvement as the ARPANET proposal was being written, his decision to become active in its implementation, and his role in the public demonstration of the ARPANET. The interview continues into Kahn's involvement with networking when he moves to IPTO in 1972, where he was responsible for the administrative and technical evolution of the ARPANET, including programs in packet radio, the development of a new network protocol (TCP/IP), and the switch to TCP/IP to connect multiple networks.
• Bio of Robert E. Kahn from the Living Internet.
• "Morning Edition" interview (NPR)
• "Nerd TV" interview (with Robert X. Cringley) - Requires QuickTime (transcript)
• Computer Networks: The Heralds of Resource Sharing, documentary ca. 1972 about the ARPANET. Includes footage of Robert E. Kahn.
• A short history of Bobs (story/slideshow) in computing, from Bob Kahn to Bob Metcalfe to Microsoft Bob and Alice & Bob
• "An Evening with Robert Kahn in conversation with Ed Feigenbaum" - Requires WMV player
• "Managing Digital Objects on the Web - Dec. 11, 2007" - The talk is available in Flash, Mpeg-4, Real Media and Windows Media formats