[2] From 1991 through to his retirement, he worked at Qualcomm in San Diego, where he specialized in wireless data networking protocols, security, and cryptography.
He is currently a board member and President Emeritus of Amateur Radio Digital Communications (ARDC), a non-profit foundation funded by the sale of part of its IP address space (44/8).
[3] ARDC manages the remaining portion of its address space by providing financial grants to amateur radio, digital communications and related groups.
In 1991, Thomas Alexander Iannelli's Master's thesis judged Karn's KA9Q NOS software as more suitable for deployment than an Air Force Institute of Technology packet radio system.
[33] Karn challenged this ruling, both in the courts and in testimony before Congress for two years, until Bill Clinton dropped almost all export controls on freely available crypto source code on January 14, 2000;[34] the judge mooted the case.