This volume contains the refereed proceedings of the Workshop on
Cryptography and Computational Number Theory, CCNT'99, which has been
held in Singapore during the week of November 22-26, 1999. The workshop
was organized by the Centre for Systems Security of the Na- tional
University of Singapore. We gratefully acknowledge the financial support
from the Singapore National Science and Technology Board under the grant
num- ber RP960668/M. The idea for this workshop grew out of the
recognition of the recent, rapid development in various areas of
cryptography and computational number the- ory. The event followed the
concept of the research programs at such well-known research
institutions as the Newton Institute (UK), Oberwolfach and Dagstuhl
(Germany), and Luminy (France). Accordingly, there were only invited
lectures at the workshop with plenty of time for informal discussions.
It was hoped and successfully achieved that the meeting would encourage
and stimulate further research in information and computer security as
well as in the design and implementation of number theoretic
cryptosystems and other related areas. Another goal of the meeting was
to stimulate collaboration and more active interaction between
mathematicians, computer scientists, practical cryptographers and
engineers in academia, industry and government.