--------------------------------------------------------------------
Douglas Stinson. Cryptography: Theory and Practice.
CRC Press. 1995 . 434 pages. ISBN 0-8493-8521-0 $67.??
Bibliography (201 items). Index.
---------------------------------------------------------------------
Stinson's book is written from the perspective of applied discrete
mathematics, making it far more theory than practice, as acknowledged
in the preface. Coverage is based on "theoretical interest and
practical importance." This means if you have trouble with math beyond
algebra, this excellent textbook will be rough sledding for you. It is
not an introductory book on cryptography. If on the other hand, you
really want to know how the algorithms work and why, it is very useful.
Unlike some other textbooks, in this one Alice and Bob handle discrete
logarithms. There are lots of theorems, lemmas, proofs and formal
definitions.

He has divided the book into three main topics, private-key
cryptography, public-key cryptography and research in cryptography.
Each chapter has notes, references and exercises. While Stinson does
not claim completeness for his book, most things are covered to some
degree. DES, RSA, hashing and ElGamal get more attention, while
Kerberos gets only a brief description. MD4 and MD5 are just small
subsets of the hash chapter.

The first three chapters are dedicated to private-key cryptography,
with the requisite classical cryptography covered in the first. If you
were intrigued by Schneier's brief explanation of Shannon's perfect
secrecy, Stinson provides more detail in a complete chapter. His good
DES chapter is the last in the private-key section.

The largest topic is public-key cryptography, with six chapters devoted
to it. The relationship of the ElGamal cryptosystem and the discrete
logarithm problem is discussed along with several other associated
algorithms, for example, Shanks' algorithm and Pohlig-Hellman. The
chapter on identification schemes presents Schnorr's, Okamoto's, and
Guillou & Quisquater's.

The active areas of research covered in the last four chapters are
authentication codes, secret sharing schemes, pseudo-random number
generation and zero-knowledge proofs. Here, again, if Schneier has
piqued your interest in the Blum-Blum-Shub generator, a much more
detailed offering is available in Stinson.

I have put this book next to Schneier's on my bookshelf. I recommend
that if you are serious about cryptography, you should do the same.
______________________________________________________________________