Cybersecurity"Zero knowledge" keeps secrets you put on the net safe

Published 18 June 2010

Intrigued by topics that touch on mathematics, computer science, physics and neuroscience, Professor Shafrira Goldwasser has made far-reaching contributions to keeping your data safe on-line; the solution she discovered used randomized methods of encoding, which came to underlie all future protocols for secure Internet transactions and data privacy

Professor Shafrira Goldwasser // Source:

If you feel secure keying your credit card information onto a Web site, you should thank Professor Shafrira Goldwasser. At the end of April, this Israeli professor traveled to Philadelphia’s Franklin Institute to accept the 2010 Benjamin Franklin Medal in Computer and Cognitive Science for her fundamental contributions to cryptography theory, the basis of techniques for encoding anything from secret messages to financial information on the Internet.

Goldwasser helped devise a “zero-knowledge” way to process information without seeing it — for example, to determine if a credit card is valid without knowing its numbers.

Israel21c’s Abigail Klein Leichman writes that the New York-born scientist, who moved to Israel with her parents when she was in the first grade, discovered an affinity for math and physics in high school. Though these were not traditionally “feminine” fields of study, her parents strongly encouraged her to pursue them. She went off to Pittsburgh’s Carnegie Mellon University after graduation.

An awakening science

Computer science was in the awakening stages then. Computers were used only by computer professionals in academia, the military, and industry. The notions of personal computers, the Internet, and engaging in continuous communication and financial transactions over the Internet did not yet exist,” Goldwasser told Leichman. “But Carnegie Mellon had a strong computer science and applied math department even then.”


She noticed a marked difference between the few female students and the majority of males in her classes. “The men who took computer science classes had tinkered with computers at home and knew something about programming, while the women had never seen a computer. However, the women were noticeably more mathematical.”

In graduate school at the University of California-Berkeley, Goldwasser delved into computational theory, classifying and defining problems that could readily be solved by computer programs. During a course on number theory, her advisor posed the question of how two people might engage in a coin toss over a computer network or phone.

Somehow this problem really intrigued me,” says Goldwasser. “I started to think about it obsessively.” She theorized that any sort of game without actual cards or playing pieces would have to involve coded messages, encryption for secrecy, and extra functionality to make virtual ‘moves’ such as choosing and discarding cards.

The foundations for e-purchasing

Putting a card down is like committing to a decision, but you only later turn it over. How do I do this so the other player can’t guess what I am doing until a later stage?” The answer she discovered was randomized methods of encoding, which came to underlie all future protocols for secure Internet transactions and data privacy.


I didn’t realize how ground-breaking it would be,” she says. “We had no notion of applications at that time.”

After Berkeley, Goldwasser studied at the Massachusetts Institute of Technology and stayed on as a professor of computer science and engineering, a post she still holds part time. She met her husband, now a professor of computer science at Tel Aviv University, while on sabbatical in Jerusalem in 1987. They married in 1992 and eventually settled in Rehovot, the city where Goldwasser works with graduate computer science and applied mathematics students at the renowned Weizmann Institute of Science.

Goldwasser is currently intrigued by topics “on the border between mathematics, computer science, physics, and neuroscience.” Her contributions to the study of why certain real-life math problems cannot be easily solved by computers has changed the way scientists study what a computer can and cannot do.

Goldwasser’s previous accolades include two Godel Prizes in theoretical computer science, the RSA Award in Mathematics (for public-key cryptography), the Association for Computing Machinery’s Grace Murray Hopper Award, and the National Science Foundation’s Presidential Young Investigator Award and Faculty Award for Women.