Cryptography is a key technology in electronic security systems.
Modern cryptograpic techniques have many uses, such as to digitally
sign documents, for access control, to implement electronic money,
and for copyright protection. Because of these important uses it is
necessary that users be able to estimate the efficiency and security
of cryptographic techniques. It is not sufficient for them to know
only how the techniques work.
This book is written for readers who want to learn about mod-
ern cryptographic algorithms and their mathematical foundation
but who do not have the necessary mathematical background. It
is my goal to explain the basic techniques of modern cryptography,
including the necessary mathematical results from linear algebra,
algebra, number theory, and probability theory. I assume only basic
mathematical knowledge.