Dear Folks: Several of you have been very helpful and considerate with me in helping me to understand the theory behind modern encryption systems as used with internet protocols and email. You have referred me to various URLs on the subject which I found indeed very interesting and informative. I have recently read an excellent book on the subject of encryption, and I would highly recommend it to anyone interested in this topic. The book title is "Code Breaking, a History and Exploration" by Rudolf Kippenhalm. This book was originally published in German. The author received his Ph.D. in mathematics from Erlangen University. He is the author also of a highly praised book "One Hundred Billion Suns". His book on code breaking covers the history of encryption from the most ancient times to the modern era. He presents many interesting anecdotes from the history of espionage and spycraft. The subject matter is explained very clearly and without perplexing the reader with highly complex mathematical formulae and algorithms. This book has answered all my questions on the theory behind the new internet encryption protocols. It is one of the most fascinating books I have read in a long time. BTW, the author says that a freeware program has been written for the PC that can turn your machine into an Enigma, the German encryption machine of World War II. He describes the program as a an Enigma simulator, and said that it was available from ftp://agn-www.infomatik.unihamburg.de/pub/cryptsim/simulators. The program is named enigma22.exe, and it is available only in a German version. It was written by Marian Kassovic, an information scientist of the University of Hamburg. I was unable to connect with this ftp site. If anyone knows of an alternate site where I might obtain this program, please post it. Of course I know that the Enigma is not modern by today's standards, but I would find the program very interesting as a matter of historical curiosity. Thanks again to all those who have helped me to understand how modern encryption systems work and have spurred my interest in this subject. found every bit of it highly fascinating -- This mail was written by user of Arachne, the Ultimate Internet Client
