Phil Karn, born October 4, 1956, is an engineer from Baltimore, Maryland. He earned a bachelor's degree in electrical engineering from Cornell University in 1978 and a master's degree in electrical engineering from Carnegie Mellon University in 1979. From 1979 until 1984, Phil Karn worked at Bell Labs in Naperville, Illinois, and Murray Hill, New Jersey. From 1984 until 1991, he was with Bell Communications Research in Morristown, New Jersey. Since 1991 he has been with Qualcomm in San Diego, where he specializes in wireless data networking protocols, security, and cryptography.
He has been an active contributor in the IETF, especially in security, but is also a strong contributor to the Internet architecture. His name is on at least 6 RFCs. He is the inventor of Karn's Algorithm, a method for calculating the round trip time for IP packet retransmission.
He is well known in the amateur radio community for his work on the KA9Q Network Operating System (NOS), named after his amateur callsign, early 9600 bit/s FSK radio modems, and more recently, the introduction of forward error correction (FEC) into the Amateur Satellite Service, with FEC applied to the 400 bit/s PSK telemetry from the now-defunct AO-40 satellite.
In June 2014, Phil Karn was interviewed for the History of the Internet Project (HOTI). Phil Karn describes his contribution to the effort to reboot the 1978 International Sun/Earth Explorer-3 (ISEE-3). The #ISEE-3 is also known as the International Cometary Explorer.
Crypto export lawsuit
In 1994, the US State Department Office of Defense Trade Control ruled that while it was legal to export Bruce Schneier's "Applied Cryptography" book under the rules for munitions export, it was illegal to export the source code in the book on electronic media such as a floppy disk.
Phil Karn challenged this ruling, both in the courts and in testimony before Congress, and the case dragged on for years, until Bill Clinton dropped almost all export controls on freely available crypto source code on January 14, 2000; The judge mooted the case, resulting in no decision and no precedent.