(Planned) Speech for a Book Party at Radcliffe Institute

Oded Goldreich [May 2004]

I wish to explain why I wanted so much to celebrate the publication of my book with you.

Books are not a central thing in my research community. They are usually not the media through which a new idea or thesis or perspective is put forward. Typically books in my field consolidate some of the basic achievements of the area, and often do not cover the more advanced achievements. Furthermore, these achievements are not necessarily of the author. The author's role is typically confined to selecting the material for presentation, organizing it and presenting it in his/her style. Sometimes the author also promotes some perspective or set of attitudes.

I feel that I deserve this party with you because I think that my book deviates from the above norm. Like in the first volume, my main aim was to promote a specific perspective and set of attitudes (see discussion below). But the current volume had required me to undertake an extensive process of reconstruction of the basic achievements, because their prior form was highly unsatisfactory. In fact, I feel that I've invested more creativity in this book than in any other work of mine.

This book is bestowed with feelings. For example, I felt it was my duty to write this book. I was haunted by a saying of my mother: "There are no privileges without duties". I felt that I've based my career on work done in this area, but this work is quite inaccessible (especially to beginners) due to unsatisfactory presentation. I felt that it is my duty to redeem this sour state of affairs, and I now feel great when thinking that I've done it!

Let me turn to another personal story. I would like to say a few words on the role that one of my personal experiences has played in the writing of my book, which being a scientific book is believed to be "impersonal" (although it isn't really impersonal, even if you only consider the dominant role of various subjective choices). Anyhow, here I refer to one personal experience that has suggested to me a metaphor that helped me shape and sharpen the exposition of my views and stress certain aspects of the book that I consider central. Following is the story.

Throughout my childhood, my father kept repeating a few sayings, and I was quite fed-up with these sayings, which at the time stroke me as mundane and certainly confined to his occupation as a civil engineer. One of these sentences was one can build a cabin with no foundations, but not a REAL building. Only a few years ago, I realized that this sentence provides an ideal metaphor for my research area, which is very remote from civil engineering and is currently called foundations of cryptography. In fact, this metaphor inspired me to promote changing the previous name of the discipline from "theoretical cryptography" to "foundations of cryptography". Furthermore, the aforementioned saying became the motto of my book (entitled "foundations of cryptography") and inspired its cover design.

Let me demonstrate to you how adequate this metaphor is by reading the first four paragraphs of the book's preface.

Cryptography is concerned with the construction of schemes that withstand any abuse: Such schemes are constructed so to maintain a desired functionality, even under malicious attempts aimed at making them deviate from their prescribed functionality.

The design of cryptographic schemes is a very difficult task. One cannot rely on intuitions regarding the typical state of the environment in which the system operates. For sure, the adversary attacking the system will try to manipulate the environment into untypical states. Nor can one be content with counter-measures designed to withstand specific attacks, because the adversary (which acts after the design of the system is completed) will try to attack the schemes in ways that are typically different from the ones envisioned by the designer. The validity of the above assertions seems self-evident, still some people hope that in practice ignoring these tautologies will not result in actual damage. Experience shows that these hopes rarely come true; cryptographic schemes based on make-believe are broken, typically sooner than later.

In view of the above, we believe that it makes little sense to make assumptions regarding the specific strategy that the adversary may use. The only assumptions that can be justified refer to the computational abilities of the adversary. Furthermore, it is our opinion that the design of cryptographic systems has to be based on firm foundations; whereas ad-hoc approaches and heuristics are a very dangerous way to go. A heuristic may make sense when the designer has a very good idea about the environment in which a scheme is to operate, yet a cryptographic scheme has to operate in a maliciously selected environment which typically transcends the designer's view.

This work is aimed at presenting firm foundations for cryptography. The foundations of cryptography are the paradigms, approaches and techniques used to conceptualize, define and provide solutions to natural ``security concerns''. We will present some of these paradigms, approaches and techniques as well as some of the fundamental results obtained using them. Our emphasis is on the clarification of fundamental concepts and on demonstrating the feasibility of solving several central cryptographic problems.

See webpages of the two-volume work, Volume 1 (published in 2001), and Volume 2 (published in 2004).