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Jim K. Omura was born on September 8, 1940, in Campbell, California, and passed away on August 29, 2024, in San Francisco, California. He was a renowned electrical engineer and information theorist.

Jim Omura earned his B.S. (1962) and M.S. (1963) degrees from MIT and his Ph.D. (1966)�� degree from Stanford University, all in electrical engineering. He spent 15 years as a professor of electrical and computer engineering at UCLA during 1969-1984, where he was recognized as an outstanding lecturer. His notable achievements include the design of several spread spectrum communication systems and the development of the Massey-Omura cryptosystem with James Massey. He co-authored the seminal textbook "Principles of Digital Communication and Coding" with Andrew Viterbi. During 1980s he was a consultant at Jet Propulsion Laboratory and contributed to the "Spread Spectrum Communications" series with Marvin Simon, Robert Scholtz, and Barry Levitt. Jim published over 100 technical papers throughout his career.

Jim made foundational contributions to information theory, channel codes, spread spectrum communication systems, and cryptography. He was a member of the �鶹��ýAV Information Theory Society and �鶹��ýAV Communications Society. In 1981, he was elevated to �鶹��ýAV Fellow status for contributions to information and communications theory as applied to communications systems design.

He dedicated his time to the �鶹��ýAV Information Theory Society (ITS) as a former chairman of the San Francisco Section, a former secretary, and a former member of the Board of Governors. He also served as editor of the �鶹��ýAV ITS Newsletter from 1973 to 1975.

Professor Thomas Kailath, who was Jim’s Ph.D. advisor at Stanford University, maintained a close friendship with him throughout his life. After Jim’s undergraduate years at MIT, Jim wanted to return to his native California. While he was considering enrolling at UC Berkeley, Professor Harry L. Van Trees suggested that Jim apply to study with Professor Thomas Kailath at Stanford. They quickly found a shared interest in advanced math in analysis and operator theory. Jim had taken courses in control theory and soon applied those ideas to get new results in the area. Jim was exposed in those courses to Bellman’s dynamic programming theory. Several years later, after Jim became an assistant professor at UCLA, Jim showed that the famous Viterbi algorithm could also be interpreted as an application of dynamic programming. Tom and Jim maintained their technical and social interactions, while Jim was away at UCLA, and these were greatly enhanced after Jim returned to the Bay Area. “Jim was not just a student; he became a lifelong friend and collaborator. I will always cherish the many technical and social events at Stanford and San Francisco at which we spent long hours discussing both work and life”, Tom shared.��

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After receiving his Ph.D. from Stanford, Jim Omura was offered a position with a three-letter agency of the U.S. Government, working at which he spent approximately one year in Southeast Asia. Returning to the States, he responded to an opening of a faculty position in the System Sciences Division of The UCLA School of Engineering and Applied Science. After an interview with various faculty, including Professor Andrew Viterbi, he accepted an offer as an Assistant Professor in the Division. Viterbi recalls working most closely with Omura on several topics: their co-authorship of the “Principles of Digital Communication and Coding”, a graduate textbook; as well as on a paper in �鶹��ýAV Transactions on Information Theory, entitled “.” Viterbi feels that “both of these were highlights of our academic careers.”��After moving on from academia to diverse entrepreneurial activities based on applications of their research, Jim and Andy stayed in touch through the decades, visiting each other in San Francisco and San Diego. Their close friendship continued through over five decades and well into their retirements.

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Jim co-founded the data security company Cylink in Sunnyvale, California in 1984, where he and his team developed the first commercial 1024-bit public key encryption chip used to secure large, commercial data networks. The Cylink Corporation went public in 1996 and was later acquired by SafeNet in 2003. During this time, Professor Martin Hellman of Stanford University frequently exchanged ideas on cryptography with Jim. Marty recalls, “Jim was not only a brilliant mind in cryptography but also a great friend. Jim’s insights always pushed the boundaries of what was possible, not only in cryptography, but also in communications more generally. For example, Jim and Dave Forney independently realized that Viterbi decoding was optimal and that it could be applied to intersymbol interference — which is just a convolutional code over the reals instead of over GF(2). I totally missed both results, but Jim saw them as “obvious.” I remember him saying that, once you understood dynamic programming, the optimality followed immediately. His enthusiasm and creativity were infectious, and his passing is a great loss to both the field and to those of us who knew him.” From 2002 to 2011, Jim served as the technology strategist for the Gordon and Betty Moore Foundation. In 2013 he co-founded dataFascia Corporation to develop an IT system for the healthcare market.

When Jim was professor at UCLA, he was the Ph.D. advisor to Dariush Divsalar and Ramin Sadr, who kept in touch with Jim through visits and email exchanges. Dariush Divsalar shared his memories of Jim: "Since I enrolled at UCLA in fall 1973, Jim taught me the fundamentals of information and communication theory and eventually guided me through the Ph.D. program. His support over the years was an intangible and critical component of all my success in my career. Jim's guidance went far beyond academics; he shaped the way I approached challenges and inspired me to pursue excellence." Ramin Sadr reflected, "Jim was far more than a professor to us over the years; he was a profound source of inspiration, a dedicated mentor, and a true friend. We experienced countless memorable moments together, from my days at UCLA as a Ph.D. student to the early days at Cylink and beyond. Jim consistently offered guidance and shared his remarkable insights throughout my career. His strength and resilience shone through in every facet of his life, including his courageous fight against cancer."�� Jim’s wife, Susan Muroshige, informed Ramin and Dariush of his passing on August 30, 2024. Susan states: “Unfortunately, the type of lymphoma he had was very difficult to eradicate, and it reappeared after several types of treatments. In July he got covid which infected his lungs and was the cause of his death.”

In 2005, Jim received the �鶹��ýAV Alexander Graham Bell Medal for contributions to the theory of communication systems and the commercial applications of spread spectrum radios and public key cryptography. He was elected to the National Academy of Engineering in 1997 for contributions to spread-spectrum communications and data encryption. He was inducted into the Silicon Valley Engineering Hall of Fame in 2009. As a university professor, corporate leader and consultant, Jim has been responsible for the theoretical underpinning and application of several benchmark technologies for communications systems and data networks during his career.

Jim’s legacy is remembered fondly by many, including his co-author Professor Robert Scholtz of USC, who described him as a wonderful friend and colleague. Professor Izhak Rubin of UCLA shared memories of working closely with Jim, whose office was next door. Izhak noted that Jim was not only a brilliant engineer and scientist but also a kind and caring person. Professor Leonard Kleinrock of UCLA shared “Jim Omura had a remarkable career and is evidenced with the other giants with whom he interacted, e.g., Viterbi, Massey, Forney, Hellman, Kailath, etc., all of whom were either my MIT classmates, or UCLA colleagues.”��

Jim is survived by his wife,��Susan; son Daniel and his wife Xiaoqing; daughter, Dawn Galperin and her husband Hernan; grandchildren Kai and Rei Omura, Natalia and Dylan Galperin; sisters Akiko Kubo and June Crow, brother George, sister-in-law Claire Omura; and seven nieces and nephews.