What unexpected or serendipitous events arose in the course of your research?

Many research discoveries in my field have such a flavor. This is probably due to the fact that the field is built upon abstract ideas and is only limited by inherent truth (rather than by experimental facts).

  What role did practical support (facilities, funding, etc.) play?

Since my research is theoretical in nature, the only support I need is a salary and a travel allowance. Travel is very important in my field, which is based on ideas, because it provides exposure to new ideas (in conferences and workshops) and allows for extensive interaction with colleges having different perspectives.

In contrast to "classical" Cryptography, which focuses on (the single problem of) providing secret communication over insecure communication media, modern Cryptography is concerned with a huge variety of problems. In fact, modern Cryptography can be defined as the study of arbitrary "abuse-resilient" systems; that is, systems that should withstand malicious attempts to make them deviate from their prescribed functionality. Established in the mid-1970s, modern Cryptography has witnessed revolutionary developments culminating in the emergence of methods for specifying and constructing general "abuse-resilient" systems. Although these achievements are very impressive, many fundamental gaps are left both in the theory and its application to practice. In fact, further extending and improving the above-mentioned methods is the main current and future goal of this field.

Much of modern Cryptography is based on the notion of computational difficulty, which is the focus of a related field, called Complexity Theory. Complexity Theory, which is a central field of Computer Science, is concerned with the general study of the intrinsic complexity of computational tasks; that is, the aim is to understand the effect of limiting natural computational resources (most notably, time) on the set of computational problems that can be solved. Although Complexity Theory has had many remarkable achievements, some of them can even be appreciated by non-experts, its open problems offer a great research agenda for the next century.

In terms of practical applications in general, some of my research contributions turned out to lead to commercial products. However, I consider the indirect (and hard to trace) impact on practice of ideas and notions suggested in my work to be far more important.

  What would you rate as your most difficult or trying professional moment?

In my field, difficult periods (say months) are more common than difficult moments, and accordingly the difficulties tend to be deeper and less dramatic. Difficult periods are long periods in which one is searching in the dark for something of which one only has a very vague idea. In addition to the intellectual difficulty of conducting such a search, it also tends to be emotionally exhausting. Specifically, often for a long period, one does not get any feeling of progress and this is very frustrating. Only in retrospect, can one sometime realize that these "bad periods" were actually periods of progress, although one did not realize it while living them. My advice to other researchers in the field is to realize that progress depends on ability to survive these unavoidable "bad periods."

  Which of your professional achievements brings you the most satisfaction?

I am most satisfied by discoveries that either reflect or carry along a deep understanding of fundamental phenomena. In particular, I find it most satisfying when a discovery is made based on such an understanding (rather than emerging by chance). I am also very satisfied when feeling that I have contributed to the understanding of other people either through my own work or through exposition of the work of others.

  Aside from your scientific career, what is your greatest or most compelling ambition in life?

To understand more about the nature of man, society, and history, and to be able to contribute to the "improvement of mankind." (Surely, my contribution will be miniscule, but I'll be content with it.)

  Would you like to leave any other comments about your work or share a personal side of yourself?

The revolutionary impact of Computing Technology on our society does not seem to yield familiarity of the wide public with the intellectual contents of the Theory of Computing. I believe that this is a pity, because the latter contains many ideas and insights that may be of general interest. My web page provides links to attempts to communicate these ideas to non-experts. Specifically, see http://www.wisdom.weizmann.ac.il/~oded/toc-sp2.html.

Dr. Oded Goldreich
Faculty of Mathematics and Computer Science
Weizmann Institute of Science
Rehovot, Israel