The title of Network Security is too broad and the subtitle too narrow: it hardly covers network security in general, but it does cover more than just secure communication. Part one is solid mathematical cryptography, explaining secret key cryptography, hashes and digests, and public key cryptography. Part two describes how these are used to build authentication protocols (with detailed discussion of Kerberos V4 and V5). Part three covers the standards for secure electronic mail (PGP, PEM and X400) and the final chapter covers a miscellany of different security systems: NetWare, KryptoKnight, DASS, Lotus Notes, DCE, Microsoft, and Clipper.

Network Security really does explain everything — even what a modulus is! — and avoids an overly mathematical approach (the more abstract number theory is consigned to a separate chapter). The authors have also done their best to make their book readable and to keep the reader entertained. Here is a fun quote:

"Humans are incapable of securely storing high-quality cryptographic keys, and they have unacceptable speed and accuracy when performing cryptographic operations. (They are also large, expensive to maintain, difficult to manage, and they pollute the environment. It is astonishing that these devices continue to be manufactured and deployed. But they are sufficiently pervasive that we must design our protocols around their limitations.)"

More importantly, the explanations are clear and well illustrated with diagrams.

Network Security is probably a bit much for the complete novice to distributed systems and cryptography, however. Much of the detail is likely to interest only protocol designers and implementors: complete descriptions of the MD5 digest algorithm (with all the constants!) and the El Gamal signature scheme are included, for example. It would be suitable as a text for graduates or higher undergraduates in mathematics or computer science (the exercises at the end of each chapter suggest this is its intended audience), and also for programmers or administrators who want to understand the security systems they are implementing or deploying.

May 1995

External links:

- buy from Amazon.com or Amazon.co.uk

Related reviews:

- Radia Perlman - Interconnections: Bridges, Routers, Switches, and Internetworking Protocols
- books about computing
- books about networking
- books published by Prentice Hall