One of the main reasons for writing this monograph is the curiosity to know more.
Identity-based encryption is a fascinating area of modern cryptography. We have
done some work in this area and wanted to explore the area in some depth. This
motivation, however, was not sufficient for us to take up the job. The catalytic effect
is due to PeterWild, who suggested us to take up this work and very kindly referred
us to Springer.
Determining the focus of a monograph is difficult. More specifically, it is difficult
to determine who would benefit from the text. Within a decade or so, identity-based
encryption has emerged as a distinct area of research starting, virtually, from scratch.
Naturally, IBE now attracts many research students from across the world. For a
beginner, it might be a little difficult to get a unified account of the evolution of this
research area from the scattered literature. It is precisely this gap that we try to fill
through this monograph.
Starting from the basic ideas, the monograph attempts to cover all the important
IBE schemes that have been proposed till date. Among these are included the more
recently proposed lattice-based IBE schemes. A major thrust of the research in IBE
is the so-called security proof. Proofs of the security reductions of most of the important
schemes are provided in details. Our guiding principle in selecting the proofs
for inclusion is that they highlight some novel techniques. Many more schemes are
described without any formal proof and in some cases an intuitive description of
the security reduction is provided. Hopefully, going through the book will help a
research student to grasp the central ideas involved in constructing IBE schemes. If
this is indeed achieved, then our efforts will have succeeded. We also hope that the
book may be useful to experts as reference for quickly looking up a particular topic.
The actual writing of the monograph took several months (and included missing
a deadline). We are thankful to Springer, especially Susan Lagerstrom-Fife for her
enthusiasm and support to the project. Jennifer Maurer looked over the manuscript
several times and provided useful feedback.
Technical feedback on the contents of the monograph were provided by several
of our colleagues and students. In fact, they formed the test cases for the judging
the usefulness of the monograph. We gratefully acknowledge the comments and feedback received from Rana Barua, Sanjay Bhattacherjee, Sherman S. M. Chow, M. Prem Laxman Das, Kishan C. Gupta, Koray Karabina and Somindu C. Ramanna.