Jack Keil Wolf, an engineer and computer theorist whose mathematical reasoning about how best to transmit and store information helped shape the digital innards of computers and other devices that power modern society, died on May 12 at his home in the La Jolla section of San Diego. He was 76.

The cause was amyloidosis, a disorder caused by the buildup of a complex protein in body tissue or organs, his daughter Sarah Wolf said.

Dr. Wolf was lionized by information theorists and won many awards recognizing his contributions to the communications networks that now lace the earth. Devices like cellphones would not exist had not thinkers like Dr. Wolf come up with their mathematical underpinnings.

“He made fundamental contributions in really all the various subdivisions of information theory,” said Paul Siegel, a professor at the University of California, San Diego, where Dr. Wolf also taught.

The Institute of Electrical and Electronics Engineers called Dr. Wolf “one of the most productive cross-fertilizers in engineering research, successfully importing techniques used in one field to obtain unexpected results in another.”

Information theorists built the intellectual foundation of the computer age by using advanced algebra to devise ways to send, receive and store data. An essential idea, from the 1940s, was the binary language of computing using only 0’s and 1’s, later refined, elaborated and extended by scientists like Dr. Wolf.

Information theorists’ most urgent mission is to condense information into the most efficient shorthand, or codes. This involves finding algorithms to turn data into electrical impulses, then to transmit those impulses and finally to decode them.

“It’s a theory of ‘how little do we need to transmit to get information across?’ ” said Andrew Viterbi, creator of the pervasive Viterbi algorithm, which clears clutter from electronic messages.

Jack Keil Wolf Credit University of California at San Diego

Dr. Viterbi said a method Dr. Wolf developed for compressing separate streams of data into a single message had uses in flash memory devices.

Dr. Wolf later made advances in data storage, removing errors and clarifying fuzzy information retrieved from magnetic disks so that more data could be stored in less space. “This is at the heart of the information revolution,” said Lawrence Larson, a colleague of Dr. Wolf’s at the University of California.

Dr. Wolf was born in Newark on March 14, 1935. He delighted in pointing out that Einstein was born on the same day and that the month and day, expressed in numbers, was the beginning of Pi, 3.14, the ratio of a circle’s circumference to its diameter.

He earned his bachelor’s degree from the University of Pennsylvania, and two master’s degrees and a Ph.D. from Princeton. He served in the Air Force and taught at New York University, the Polytechnic Institute of Brooklyn and the University of Massachusetts at Amherst before moving to San Diego.

His most important early work was devising a theorem with David Slepian in 1973 proving that two separate streams of correlated data can be sent independently and simultaneously and then combined and simplified at journey’s end. An example would be neighboring temperature sensors independently sending data to a weather center. Decades later, building on the work of other theorists and engineers, the technique propelled the development of computer networks.

“It sometimes take decades for the implementation of a technology to catch up with the concept,” Dr. Viterbi said.

Dr. Wolf was recruited by the University of California, San Diego for its new Center for Magnetic Recording Research in the mid-1980s. He said in a recent lecture that he knew nothing about magnetic recording at the time, and even mispronounced the word “coercivity,” which refers to a magnetic field’s intensity.

Scientists then thought magnetic recording was boring, he said, adding, “Very smart people are sometimes wrong.”

The center’s research helped increase the speed and capacity of magnetic hard drives while lowering their cost. Dozens of Dr. Wolf’s protégés, nicknamed “the Wolf pack,” fanned out to high-level, high-tech positions. Dr. Wolf was elected to the national academies of both engineering and science.

In addition to his daughter Sarah, Dr. Wolf is survived by his wife, the former Toby Katz; another daughter, Jill Wolf; his sons Joseph and Jay; and five grandchildren.

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