The Israeli Professor Who Actually Made the World a Better Place With Data Compression

Jacob Ziv created what we call ‘lossless’ compression and laid the ground for everything from GIF to PDF, to ZIP and MP3 files. Surprisingly, it didn’t make him rich

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Prof. Jacob Ziv helped lay the groundwork for the files that make the internet what it is - from PDFs to MP3s, 'lossless' compression changed tech forever
Prof. Jacob Ziv helped lay the groundwork for the files that make the internet what it is - from PDFs to MP3s, 'lossless' compression changed tech forever Credit: Eyal Toueg

The personal story of Jacob Ziv, 89, is woven into the fabric of Israeli high-tech’s history. You’ve probably never heard of him, but you have certainly used technology based on his mathematical inventions - most famously lossless compression of data which enables us to use files like PDF, GIF, MP3 and countless others.

Ziv was one of the first Israeli scientists who completed their doctoral studies abroad and returned to teach at the Technion – Israel Institute of Technology, in Haifa. He introduced the use of transistors at Rafael Advanced Defense Systems, headed the Planning and Budgeting Committee of the Council for Higher Education and served as president of the National Academy of Sciences. He did his military reserve service in the special operations department of Military Intelligence (today's Unit 81) and he even managed to found a startup together with the veteran tech entrepreneur and investor Joseph "Yossi" Vardi. 

Ziv was born in Tiberias and moved to the Tel Aviv suburb of Ra'anana at the age of 3, where his father was the principal of the town's first school. His mother had studied literature in Moscow, and in Israel she worked in the Council of Women Workers in the country’s main labor federation, the Histadrut. His parents were expelled from the Soviet Union in 1927, together with his elder brother, who went on to establish the army's education department. 

From a young age Ziv was attracted to technical subjects. His first experiment in the field came when, at the age of 8, he turned the music stand used for his violin lessons into a floor lamp, which he gave to his parents as a gift. "My parents loved it, and they called the lamp Yankeleh," he recalls, laughing.

When he was 11, he found in his parents' library a book in Russian with descriptions and photographs of the world’s first radio transmitter. Since he didn't read Russian well, Ziv painstakingly translated the pages using a Russian-Hebrew dictionary. He even built the device himself, and improvised a prototype using a metal spool of medical tape and two balls he made from door knobs. “The famous spark was supposed to jump” across the space between the knobs, he explains. At the first opportunity that his parents left the house, he plugged the device into an electrical socket – causing, of course, a din and a short circuit in the home.

Guglielmo Marconi's radio transmitter was the first in the world and it inspired a young Ziv to build one of his ownCredit: Communication Museum

Ziv's first experiment failed, but nearly eight decades later his contribution to engineering puts him in the same class with pioneers as Guglielmo Marconi, who first invented the transistor that Ziv tried to build. In November, he was named the winner of the Institute of Electrical and Electronics Engineers Medal of Honor for 2021, becoming the first Israeli to win the prestigious award. Past winners include Marconi himself (1920); Claude Shannon, known as "the father of information theory" (1966); Jack Kilby, a co-inventor of the first integrated circuit, or microchip (1986); Gordon Moore, the co-founder of Intel and the author of Moore's law (2008).

It wasn't the first important honor that Ziv has received. In the 1970s he was awarded the Israel Defense Award twice. In 1993 he was awarded the Israel Prize for the exact sciences and in 2008 he received the BBVA Foundation Frontiers of Knowledge Award  – the award with the largest cash prize, after the Nobel awards, of 400,000 euros – in the category of Information and Communication Technologies. A rather modest sum for someone who gave the world, without recompense, an unprecedented technology that makes it possible to transmit files at high speed without any loss of data.

Why do pilots shorten routes?

Ziv attended Tel Aviv’s Herzliya Gymnasium for high school. At the young age of 16, he was drafted into the IDF, following the outbreak of the War of Independence. His first job was guarding members of the pre-state Irgun militia, who were arrested shortly after the Altalena affair which saw the Israeli arm assert its dominance over the militias. Although only a teenager, he was treated as a soldier and enjoyed a steady supply of Canadian cigarettes, which he traded with the detainees for chocolate bars.

After this brief stint as a gaurd, Ziv, who had just received a placement for training in a meteorology course, decided to take things into his own hands. "I heard that there is a radar technician course in Tel Aviv, and I believed it was a more suitable position for me," he explains. "There was a mess because I entered the course on my own accord and without a permit, but in the end, it worked out." At the end of the course, Ziv was put in command of a U.S.-made mobile radar system. The radar consisted of three boxes, each measuring one meter by a meter, on which a rotating antenna was mounted. Ziv was in charge of the assembly and operation of the radar.

Ziv's career as a radar technician has been quite successful, at least on paper. Its zenith came when he was honored by the Air Force commander for his vigilance when he noticed Israeli pilots would shorten their flight paths without permission and pass over the Gaza Strip. Shamefully, it later turned out that his excellence stemmed from an error: "I alligned the map with my eye, I didn't have a compass, but only a knowledge of Israeli territory. It turned out that I moved it too far to the right," he laughs. 

From Haifa to Tel Aviv

Ziv met Abraham Lempel, his partner in developing the groundbreaking compression algorithm, during reserve duty in what we today call Unit 81. Both were already working at the Technion, but it was during the long drives between Haifa and the base in Tel Aviv that they became friends. Zohar Zisapel was Ziv's student at the Technion and the unit's professional commander at the time. Zisapel says that everything he knows about the field of communications is based on the tutoring sessions that Ziv gave him during their reserve duty together.

From right to left: Prof. Abraham Lempel, Qualcomm founder Prof. Andrew Viterbi and Prof. ZivCredit: Technion

Zisapel plays a prominent role in the history of Israeli high-tech. The Rad-Bynet Group, which he founded with his brother, is considered a hothouse for Israeli entrepreneurs. "[Ziv] is modest and quiet. He would be walking around at the Technion, and if you didn't know who he was you might have asked him to make you a cup of tea, thinking he was the caretaker," Zisapel recalls. "When you met him in a small group and were able to take his measure, it was absolutely clear that he was the smartest person in the room," he says.

"He was also a leader, and from the moment we were able to bring him into the unit for reserve duty, it was very easy to recruit all the other lecturers at the Technion. There was a period when on Thursdays a bus would be sent from the Technion to pick up all the faculty members for reserve duty," Zisapel adds. 

 In 1975, Ziv and Lempel sat down together to prove a mathematical statement in the area of data compression. The ability to compress data already existed but the two allowed compression at a speed and efficiency without losing any data in the process. The novelty of the Lempel-Ziv  algorithm, released in 1977, is that it can compress data "on the fly", unlike previous algorithms that needed to read the file from beginning to end before they could begin compressing it. (See video for full explanation)

“You could think we sat cloistered in a room for a few weeks cracking a mathematical problem, but it wasn’t as easy as it sounds,” says Ziv. “It took us about two years of arguments and discussions.”

Ziv and Lempel didn’t patent their algorithm because at the time it was not possible to patent software, only hardware. The algorithm built their reputation and served as a basis for numerous developments. But on the day the U.S. law changed to allow patenting software, a small Los Angeles firm jumped at the opportunity to do so and began to ask for royalties from companies using the development. Their target was Microsoft, which had just incorporated a product based on Ziv and Lempel’s algorithm into its operating system.

Prof. Zvi in 1971. 'His generation felt like they were building the country 24/7. Every wire and circuit was a Zionist act for them.'Credit: Courtesy of the Technion

The two companies asked the Israeli researchers to consult them and to testify as expert witnesses in court.  “The small company, who’s name I don’t remember, invited us for a visit,” Ziv recalls. “They had two auditoriums used for lectures – one of them was named Lempel and the other Ziv. It was funny.”

He said the company had ties with Jewish contributors who started giving them what he terms a guilt trip. But he and his partner decided ultimately to go with Microsoft. “First, because we knew there wasn’t anything in it for us and that in Microsoft it would be put more extensively to public use. Second, because they paid a lot,” he says.

The consulting agreement they signed stipulated they would be paid by the hour, including flight time. But on the way to the United States their plane was grounded due to snow storms, forcing them to wait for many hours in the airport. “Thousands of passengers were stuck, but we were pleased as punch – we were being well paid for the wait,” he says laughing.

Bill Gates himself appeared in court”, Ziv continues. “He came with a shirt with the words ‘I came, I saw, I bought’ on it. The judge threw him out and told him to change his shirt. In the end Gates did exactly what he came to do – he bought the rival company and had exclusive rights to the patent and the income.”

Bill Gates. Ziv's compression played a key role in the company's history and he himself even served as its consultant after Microsoft bought the company that had patented Ziv's developmentCredit: REUTERS

Later Ziv developed another algorithm, this time with Aaron Wyner, a colleague from Bell Laboratories. The algorithm enables compressing many photos from various cameras, for example in football games, and broadcasting them simultaneously. “It’s for when you allow compression with distortions and errors to increase the broadcasting pace or to reduce the memory volume storing the data,” says Ziv.

Between military and science 

The Technion plays a major role in Ziv’s life story. He started out as an electrical engineering student in 1950, which at the time he jokes was a training ground for the future engineers of Israel’s electric corporation. “We learned the electro-magnetic theory very well, but there was no trace of what is called electronics today,” he says. After graduating Ziv joined the Masters program, which combined an internship in the Defense Ministry’s science department, which later became the defense contractor Rafael. His manager was Professor David Bergman, David Ben-Gurion's scientific advisor. “He was in the reactor affairs and everything scientific in Israel was done according to what he said,” Ziv says. “I mention him because he made a revolutionary contribution to Israel’s technological development.”

According to Ziv, In those years talented youngsters who “knew they didn’t know anything” came to work in Rafael. “We all knew we had to raise the standard in order to develop the systems we were tasked with developing, so we taught ourselves like you learn in the ultra-Orthodox haider. We’d sit and study together pouring over book after book, because there was no other choice. The entire electronics field wasn’t familiar to us from the Technion.”

Ziv with Prof. Moshe Zakai in 1973. Together the two developed a system to help disrupt missiles Credit: Technion

Bergman, he says, had a long term policy of sending promising young people who worked at Rafael to study abroad any scientific field of their interest – mathematics, chemistry, engineering, computer science. He had all their expenses covered, including living costs, as long as they studied at a prestigious university and promised to return to Israel within two years. Ziv received the scholarship and studied for his Ph.D in MIT.

“We all returned  and became Technion staff members. That created the first revolution in the electrical engineering faculty, because we all opened up abroad to disciplines that hadn’t existed in the faculty at the time.”

These days Ziv is concerned by the shortage in research funding and the dependence on grants. He says the staff’s promotion in academic institutions currently depends on the number of their publications and the funds they managed to achieve for themselves. “There’s an abundance of hundreds, maybe thousands of magazines that will publish any study. And due to this ‘publish or perish’ dynamic, researchers don’t have time to think quietly and thoroughly,” he says.

“My work with Avrham Lempel took years, we had time, nobody pushed us. I have quite a few papers, and some are highly cited, but I’m not sure I’d get a professorship today. This of course is a global, not Israeli, problem.”

Ziv has a deep fear of Israel's budget for higher education’s budget, planned six years ahead and ending this year. “It’s difficult for the government to slash in places where the money goes to wages and not to equipment and grants. Research money that goes to researchers is easy to cut,” he says, voicing his concern at more budget cuts.

Ziv believes the committee overseeing the budget has conflicting interests: It rewards institutions for integrating minorities like women, Arabs and ultra-Orthodox people due to social considerations. In contrast, it hands out money to a small number of people vetted by a small group, because it wants to promote outstanding research due to scientific considerations. “These are two different economies,” he says. “One is social-democrat and the other is liberal.”

Zohar Zisapel: 'Zvi taught me everything I know about communication'Credit: Ofer Vaknin

He suggests allocating a minimal percentage of the committee’s budget for research. “This way at least there’ll be a link between the budget and the investment in research excellence.”

Thanks to Howard Hughes

Ziv nonetheless managed to taste some of the dynamics of the world of entrepreneurship, and even to enjoy a small exit, thanks to a new graduate he recruited to Rafael at the end of the 60s named Yossi Vardi (78), the so called godfather of the Israeli high tech industry. 

Vardi made his name years later when he helped his son, Arik, set up Mirabilis, which developed the ICQ instant messaging software and was sold in 1998 to the giant AOL for $407 million. Mirabilis was in fact the first internet exit in Israel and made Vardi the fortune that upgraded him from consultant to a venture capital investor. 

Yossi Vardi at the 2015 Digital Life Design conference in Tel AvivCredit: Eyal Toueg

Ziv says Vardi was a “mischievous student” of industrial engineering and management at the Technion, who was eager to work with him in Rafael, only because in the admission interview he had given him a probability problem Vardi couldn’t solve. Two years later, in 1969, Vardi added Ziv to a startup he had set up called Tekem (a Hebrew synonym for Advanced Technology) and was one of Israel’s first software development firms. Tekem grew and became a 300-employee company which was eventually sold to Tadiran and later it served as the basis for Ness Technologies

In its early days the company underwent several upheavals. In the Yom Kippur War, when most of its workers were called up, the company almost collapsed and Ziv had to mortgage his apartment to get a loan from the bank. He says Tekem was saved by the American flight pioneer and movie producer Howard Hughes, who had been one of the Air Force’s major suppliers. He had been asked to invest in an Israeli company to show he had business dealings in the country. Fortunately, he chose Tekem.

Ziv says he made a profit from Tekem’s sale to Tadiran, but not in today’s standards. “It wasn’t millions. But I remember going to the bank in Haifa and it made a huge impression on the banker.”

Vardi tells it a little differently. He says that when he graduated from the Technion in 1967 he saw an ad for an electronics engineer with management experience with the address of “P.O.Box 1 Kiryat Motzkin,” the code name for Rafael. Vardi, who had been an electronics technician in the army and a radio buff, wanted the job and sent a letter to Rafael telling them they weren’t looking for an electronics engineer with management experience, but for a manager with electronics experience. Ziv, who was then the head of Communications, was amused by the letter and invited the young man for an interview. “After the interview I became Jacob’s (Ziv) administrative assistant and was forced to make major decisions like what size table an engineer needs,” Vardi says jokingly.

"There are a lot of smart people, but I really don't think I’ve ever met someone at Jacob’s level,” Vardi continues. “He is both extremely pleasant and empathetic and people would listen to him not because he had official authority but because they had massive respect for him as well as being extremely fond of him.

“Jacob and his generation felt like they were building the country 24 hours a day, seven days a week, every wire and circuit was a Zionist act for them. The logic of their work was always ‘what solution will lead to the most economic and defense benefit for Israel.’ They perceived themselves not just as building a technological infrastructure, but also a human one. During the days they worked on development, and in the evening they trained the next generation of engineers in the Technion.”

Ziv is married to Shoshana, a former rymethics teacher. They raised their four children in Haifa, but a decade ago, in wake of his deteriorating vision as a result of a hereditary disease, the couple moved to the central Israeli suburb of Kfar Saba, next door their youngest daughter. Until about two years ago, Ziv was still able to read from a computer screen, but since then he has lost most of his sight and today is almost completely blind. 

Today Prof. Ziv is almost blind, but still makes an effort to read and stay abreast in the field. Credit: Eyal Toueg

“I have an OrCam device,” he explains about the technology developed by the founders of Mobileye that latches onto glasses to help those with compromised vision. “I liked it a lot but it is only good for those whose imparied vision still allows them, for example, to see they are standing in front of a street sign or holding a bottle of pills, but can’t read what they say. Today, I use it only occasionally, when I want to read my income tax reports. What I really want to read is technical materials, but sadly it can’t help me with that,” Ziv laments. 

Every afternoon, Ziv calls his eldest son, Noam, who lives in California, and he reads his father his emails and takes responses via dictation. Noam works in hitech and is a biotech consultant. His second daughter, Michal Ziv-Ukelson is a computer science professor at Ben Gurion University in the Negev. His third son, Atai, obtained a doctorate in economics and is today the head of a company called SolidRun which creates micro computers that cost only $45. Their youngest, Vered Reuben, studied Chinese at the Hebrew University in Jerusalem. She too now works in tech, albeit in a sales position. 

Ziv still makes an effort to stay abreast in his field and he spends his time ‘reading’ with the help of audio books based on the MP3 technology he helped lay the groundwork for during the 1970s. He also has a subscription to his local library for the blind and in conversation he is still sharp and articulate, always glad to talk about literature. “Currently, I am reading Tara Westover’s book ‘Educated’, about her being raised by Mormons in Idaho while hiding from the authorities. Until the age of 17 she never even heard of the Holocaust,” he says about the book. Before that he read “Borderless Leadership”, the Hebrew-language biography of Henrietta Sold. He says that sometimes he likes to read thrillers, but jokes that “after ten bodies in one week, I’ve usually had enough.”