This is an undergraduate textbook rather than a book aimed at the professional programmer or network administrator. The topic coverage is wide - block cipher and public-key encryption algorithms, security issues for network administration, network security schemes (e.g., Kerberos, PGP, SSL, etc.). Unfortunately, the coverage of each topic is also narrow. The cryptography section, for example, is no match for Bruce Schneier's 'Applied Cryptography'. In addition, the coverage is not always clear; for example, the section on SSL/TLS is no clearer than Netscape's SSL (secure sockets layer) specification (i.e. not very clear at all). There is also a lack of application, although this is addressed to some degree by the set exercises. However, the professional developer has no time for exercises and code examples would be much better. Overall the book is OK, if a little disappointing. It gathers a wide range of material under one cover but cannot be used as a definitive reference for any topic. Better for computer science students than IT professionals.