I found the material included in this book to be an interesting collection of topics of applied mathematics in the area of cryptography. The book contains an admirable discussion of the stochastic views of cryptography. The material is by no means at the cutting edge of technology. However, it provides an adequate background for the novice reader in this important area of research. For me, the most interesting chapters were those describing information theory, tests for pseudorandom number generators, cryptanalysis, semantic security and birthday attack.

I would urge that more attention to details and typographical errors is to be considered for future prints. As an example; the word "und" on page 78 seventh line!