Preface: Revolutionary developments which took place in the previous decade have transformed cryptography from a semi-scientific discipline to a respectable field in theoretical Computer Science. In particular, concepts such as computational indistinguishability, pseudorandomness and zero-knowledge interactive proofs were introduced, and classical notions as secure encryption and unforgeable signatures were placed on sound grounds.
Our intention was to write a book that presents the basic concepts, definitions and results in cryptography. In a first burst of energy, most of the material appearing in these fragments was written, but since then very little progress has been done. Thus, I see it preferable to place these fragments in public domain rather than wait till the original plan is completed.
These fragments contain a first draft for three major chapters and an introduction chapter. The three chapters are the chapters on computational difficulty (or one-way functions), pseudorandom generators and zero-knowledge. These chapters are quite complete with the exception that the zero-knowledge chapter misses the planned section on non-interactive zero-knowledge. However, none of these chapters has been carefully proofread and I expect them to be full of various mistakes ranging from spelling and grammatical mistakes to minor technical inaccuracies. I hope and believe that they are no fatal mistakes, but I cannot guarantee this either.
In addition, the fragments contain an old annotated list of references (compiled mostly in February 1989). Again, I feel that something incomplete is better than nothing.
Tel-Aviv, February 1995.
Organization: The following postscript files are available on-line
Additional material can be found in my Lecture Notes on Foundations of Crptography (1989).
See also errors in the fragments and news regarding the fragments (updated 2/96).