While the general public may not realise this yet, encryption is one of the most important political issues affecting us all at the beginning of the next century. In the past, you were most likely to come across encryption while reading a spy-novel on the beach; today, you rely on encryption every time you use you web browser or use a cash point - and this is only the beginning. Both electronic commerce and electronic communications crucially rely on secure encryption and both are becoming more prevalent in our lives.

The battle between those that want secure encryption available to the common people and those who want to exercise state control to stop this has been raging largely unnoticed for years, surfacing only briefly in skirmishes such as the Clipper chip and the Zimmerman/PGP trial. This book describes, in detail, the modern history of this political battle. Inevitably, the focus is largely on the development in the USA and the European and international situation is relegated to a small - but interesting - section. Usually this would draw criticism from me, but in this case it is probably justified. The US is by far the leader in this field and their policies tend to dominate and lead other national policies. So while more international information would be interesting, this will probably have to wait for another book.

This book is a history of the politics of the subject. Although its outlines the workings of some simple ciphers, it does not even attempt to describe the workings of their modern counterparts. If that is what you are looking for, you have to look elsewhere ( Applied Cryptography (2nd ed) : Protocols, Algorithms and Source Code in C , by Bruce Schneier, Addison Wesley, 1996 could be a good first choice). It does, however give you a basic idea of what public key encryption is all about, and why it is important.

In summary, therefore: If you want to learn about the history and politics of encryption and wiretapping, mainly in the US, this book is a prime resource.