One of World War II's great secrets, the breaking of the German Enigma ciphers at the British intelligence center at Bletchley Park, has been become a fertile source of both historical and fictional accounts. Hugh Sebag-Monterfiore's "Enigma: The Battle for the Code" finds a intriguing niche in the middle of that spectrum.

Sebag-Montefiore expands the story of codebreaking at Bletchley Park to include the efforts from the 1930s through the end of the war by the Poles, French, British, and Americans to steal phyiscal Enigma machines and machine components, codebooks, and messages from the Germans. This chase took place all over Europe and at sea around the world. The sea chase involves the ambush of German ships and submarines to seize their code materials. The pursuit was made all the more hazardous by the danger that the Germans might learn Enigma had been compromised.

Sebag-Montefiore nicely mixes an understandable and very human account of the codebreaking with the large espionage effort against the Enigma. Many of the events at sea read like chapters out of a James Bond novel, rather than the excellent popular history that is this book. There is more than enough detail to interest serious students of the intelligence business, and enough daring-do to entertain the general reader. "Enigma: The Battle for the Code" is highly recommended to both. This edition comes with a nice selection of photographs and some detailed appendices on the techniques of codebreaking.

There are two themes to this book, the methods used to break the German enigma machine cipher and the capture of code books that aided in this process. As such, the book contains both a lot of technical information on machine ciphering/deciphering and exciting chapters dealing with the capturing of German submarines and some surface ships; both are critical aspects of the story of how the German enigma messages were deciphered. The book focuses almost exclusively on the naval machine, which was both more technically complex and utilized more complex encoding procedures than that of the German Army and Air force machines. The breaking of the naval code was made easier by the ability to capture code books from submarines and small surface ships (weather ships, trawlers, etc.). This, as is discussed in the book, was a two edged sword, as the whole enigma deciphering program might be placed in jeopardy if the Germans learned of these captures. Fortunately, the Germans believed that even such captures would be of only modest value because of the complexity of the machines and the procedures that were employed. At most, it was believed that code books would be of only short-term value, since the machine settings and tables were frequently changed making a stolen code book soon obsolete.

The Germans did not realize that Polish and then British mathematicians had uncovered weaknesses in the enigma system, and that these weaknesses allowed the ciphers to be broken even without code books (although at times these code books were invaluable). This book explains how this was done, both in the body of the text and at greater length in a series of appendices. (This aspect of the book is very complex and technical, which some readers might find a bit tedious and off-putting.) The book also tells the exciting stories of very brave British sailors (and some Americans) going down into sinking submarines to retrieve code books and enigma machines, all the while aware that scuttling charges might go off killing them outright or trapping them in a very much more rapidly sinking submarine (from which they would not be able to escape); indeed some did not escape. Some of the book also focuses on spies and counter spies and how a German sold the secret of the enigma machine to the French, how this aided the Polish code breakers before the start of the war, the subsequent German attempts (mostly successful) to capture the French and Polish code breakers, and finally why they did not learn enough from these captures to stop using the enigma machines.

As noted, this is largely the story of British code breakers, working on the German naval ciphers. There is some reference to work with the Americans and work on other German ciphers. I recommend Budiansky's Battle of Wits for information on the American collaboration with the British, efforts of the British and Americans to break the German Army and Air force enigma machines and the American work on Japanese codes and ciphers.

I recommend this book to those interested in the history of WWII and to those interested in codes and ciphers. Those who just want an exciting story of spies and adventure on the high seas may find the more than half of the book that is very technically oriented to detract from what they are seeking and they therefore might be disappointed. Likewise, those only looking for technical information may find the adventure parts of the book distracting.

Very thorough look at the breaking of the Enigma code...A bit heavy on the actual mechanics of the device itself, which was hard to follow; otherwise an interesting look into history.

A tedious and poorly organised account of a fabulously interesting history. Other reviewers have writen accurately about this book's good qualities but none have told how gripping it could be for a few pages and how absolutely bloodless and irritating it could turn for the next 10, leaving this reader frustrated, wanting the author to finish his present narrative (sometimes of treason and spies) before going onto the next stage of his story. Then there are the many pages of how the enigma machines actually worked. Perhaps code-breakers could follow it, but it was (again to this reader) writing as clear as mud -- descriptive writing so incredibly turgid as to make one read it aloud and laugh.

I recently became interested in the history of World War II. I was looking for a good book about the subject to read and I stumbled upon this one. Also having a degree in computer science and mathematics I decided this was the book for me.

I have never read a history book like this before and wasn't really sure how I would like it. So far I have absolutely loved it.

You would expect the pacing and dialog to be very slow and boring but that is not the case at all. This book has held my interest thoroughly from the start.

I enjoyed this "chatty" (typically British, public school style) account of how Enigma was broken and constantly re-broken as the Nazi's upgraded their systems over the course of the conflict. Seabag-Montefiore has done his homework providing a well researched account of Bletchleys Park's major contributions at many decisive turning points in WWII. He also shone some light on many of the "front line" Polish and French agents and controllers who provided vital intelligence about the key inner-workings of the actual Enigma "typewriting" machines at the beginning of the war. Following their exploits through to their ends provided a human face to those heroic individuals surviving after occupation. Reasonably footnoted and sprinkled with a number of first-person accounts gained though increasingly rare interviews. Extensive appendices provide a good primer on the main cryptographic problems encountered and the various work-arounds the code-breakers discovered. All in all a well rounded history of the contributions made by British intelligence and others to the defeat of Hitlers mad ambitions.

I enjoyed this "chatty" (typically British, public school style) account of how Enigma was broken and constantly re-broken as the Nazi's upgraded their systems over the course of the conflict. Seabag-Montefiore has done his homework providing a well researched account of Bletchleys Park's major contributions at many decisive turning points in WWII. He also shone some light on many of the "front line" Polish and French agents and controllers who provided vital intelligence about the key inner-workings of the actual Enigma "typewriting" machines at the beginning of the war. Following their exploits through to their ends provided a human face to those heroic individuals surviving after occupation. Reasonably footnoted and sprinkled with a number of first-person accounts gained though increasingly rare interviews. Extensive appendices provide a good primer on the main cryptographic problems encountered and the various work-arounds the code-breakers discovered. All in all a well rounded history of the contributions made by British intelligence and others to the defeat of Hitlers mad ambitions.

Without a doubt the Allies' cracking the German enigma is one of the greatest, and perhaps the deciding, accomplishment of World War Two. Winston Churchill called the cryptanalysts at Bletchley Park the geese who consistently laid golden eggs, without ever cackling.

This history of the battle to break the naval enigma is a good book; thorough, well-researched, not excessively tedious (because the technical details are relegated to appendices.) All the same, I found the book to be akin to reading a corporate history; the capture of U-boats and other boats with code books, the sinking of ships, and betrayal of secrets becomes repetitive. If this really interests you, you'll really like the book. Alas, I think that a good book could have been a great book if it had also gone into further detail than to simply mention that the Germans had also cracked some of the Allies' naval codes.

Crypto and history buffs will enjoy this book; the less enthusiastic will probably find it a slog.

Mr Sebag-Montefiore is an excellent story teller. It is diffcult to put this book aside.

In contrast to other books on Enigma the technical details of the breaking are given in Appendixes, which makes reading easier. This is a very good idea.

My only qualm is that the story is mainly that of the navy Enigma. Little is devoted to the air force and army Enigma, which is a pity.

Mr Sebag-Montefiore is an excellent story teller. It is diffcult to put this book aside.

In contrast to other books on Enigma the technical details of the breaking are given in Appendixes, which makes reading easier. This is a very good idea.

My only qualm is that the story is mainly that of the navy Enigma. Little is devoted to the air force and army Enigma, which is a pity.

The Ultra secret was kept for a long time after WWII. Recently declassified, it was the Allied code name for the Enigma ciphering system used by the Germans to coordinate U-boat attacks, to gather weather reports and intellegence, etc. This book is interesting in that the author gives ample space to the sailors and intellegence officers that gathered hard data, often from sinking U-boats, instead of focussing exclusively on the technical work performed at Bletchley Park. The result is an action-packed account that speeds through the material, while giving the reader a glimpse at the personalities and actions of the people responsible for solving the Enigma.

The book is arranged roughly chronologically, but Sebag-Montefiore divides his chapters into subject areas that span months at a time. This makes for a better flow. Therefore, the book backtracks from time-to-time, but it is never confusing, due to the skill of the author (and his editor). Oft-neglected episodes are included, much to the benefit of the book - because the U.S. and Britain were the two largest Allied powers, many books overlook contributions by other nations. Not so with this book - the Polish codebreakers that originally duplicated the Enigma and broke the peacetime ciphers are given more space than the celebrated Alan Turing. Likewise, the Canadian contribution to convoy duty (and therefore U-boat hunting and intellegence gathering from sinking U-boats) is given its rightful share of space.

The author wisely keeps the pace moving with events and doesn't allow the narrative to bog down in technical descriptions of the deciphering procedures. These procedures are gathered as appendices at the end of the book. The appendices are not great - they are descriptive without going into the mathematical detail, and therefore come across as "hand-waving." Luckily this difficulty does not detract from the main part of the book, so is not a fatal flaw, but those looking for a technical explanation should look elsewhere.

"Enigma" by Hugh Sebag-Montefiore is an up-to-date look at the history of the cracking of the code, from the initial efforts in Poland through the final changes the German's made in May of 1945. The most impressive thing about this book is how comprehensive it is. The author covers all of the aspects of the code-breaking effort. Including some of the technical details involved in breaking the code, the personalities of those involved, the stories of their efforts to capture code books and equipment, and the effects that their efforts had on the war. The book is arranged in chronological order, with appendixes provided to give more of the detail of the technical aspects. The epilogue includes a wrap-up of what happened to the major participants after the war. This is a very worthwhile read for anyone interested in World War II and Enigma.

Whereas many other books concerned with Enigma have concentrated on the work of the cryptanalysts of Bletchley Park this deals with those other people crucial to the effort. The seamen of the Royal Navy, secret agents, Polish cryptanalysts and ironically the Germans.

If you are after the technical details of how Enigma worked and how it was cracked then don't get this book. But if you are interested in reading a gripping account of the events surrounding the Battle for the Code and the consequences thereof then this is a must.

Sebag-Montefiore has compiled outstanding source and reference materials to give the human story behind the code breaking efforts by the British. The bravery of the men of the Royal Navy who risked life and limb to steal codebooks and Enigma machines from German warships and submarines. Also covered are the details of the steps that the Germans took to "secure" their code that often backfired making it easier to break and the incompetance of some German radio operators that also compromised security.

Whereas many other books concerned with Enigma have concentrated on the work of the cryptanalysts of Bletchley Park this deals with those other people crucial to the effort. The seamen of the Royal Navy, secret agents, Polish cryptanalysts and ironically the Germans.

If you are after the technical details of how Enigma worked and how it was cracked then don't get this book. But if you are interested in reading a gripping account of the events surrounding the Battle for the Code and the consequences thereof then this is a must.

Sebag-Montefiore has compiled outstanding source and reference materials to give the human story behind the code breaking efforts by the British. The bravery of the men of the Royal Navy who risked life and limb to steal codebooks and Enigma machines from German warships and submarines. Also covered are the details of the steps that the Germans took to "secure" their code that often backfired making it easier to break and the incompetance of some German radio operators that also compromised security.

Once I picked this book up, it was very hard to put down. Sebag-Montefiore has compiled a gripping glimpse into the code breaking efforts by the British. His source and reference material are outstanding and his explanations of the technical aspects are gentle enough for the non-cryptologist to follow. I felt his technical analysis was just right, enough to let me understand the problems the Bletchly Park code breakers faced, while not to technical for me to lose interest.

Those wanting a in depth review of the methods used may want to look elsewhere, but I believe this book details the human story behind Bletchly Park's success masterfully. It's amazing to me that despite the capability of the Enigma machine, its ultimate Achilles heel was that it was operated by humans, who are in the end non-random and prone to habit. The eccentricities of the code breakers, the stiff British upper lip, and the maverick attitude of the US code breakers are all displayed for the reader.

The exploits of the Royal Navy is nothing short of truly heroic in their efforts to obtain code books to aid Bletchly's cause. It's ironic that the Enigma was first broken by three Polish mathematicians, who have never received much credit.

A fascinating book on exploits that had far reaching consequences after the end of WWII. Strongest recomendation.

This is an excellent history of code breaking during World War II. The majority of the book is from the British perspective. It is action packed. If you are looking for the math behind the code breaking, this is not the book.

Some key points are:
-Code breaking of enigma much sooner than I had known.

-Steps that the Germans took to "secure" their code often backfired and made it easier to break.

-We are all human. Human habits were key to breaking the codes.

-The code breaking was a key weapon in WWII.

This book whet my appetite. I hope the author writes more. Possible topics include:
-German code breaking. Too many teasers in this book about the German code breakers.. I want more details.

-US code breaking of Japan and Germany.

-The hints of the French activity left me wanting to know more.

Overall I enjoyed the book. I would recommend it to history buffs and math buffs (too few books where mathematics and mathematicians are the heros.)

It's remarkable that 60 years on new information continues to surface about the breaking of the Enigma code. Having followed much of the "new material" released over the last 20 years in books and films it is great to see other key players in the Enigma drama getting due credit.

Forget about the crude attempts by Hollywood in the film U-571 to credit the americans with breaking the code, and read this book to find out about the huge contributions by the Poles (who were breaking Enigma in the early 1930's), the British and Canadian seaman (boarding subs and weather reporting trawlers to capture code books), and the French.

This book is not for those who want a deep understanding of deciphering techniques used at Bletchly Park - this is covered in other exellent volumes (see Sarah Flannery's book "In code: A mathematical journey" if you want a gentle introduction to cryptography ). It does give detailed and personal accounts of the risks taken by others in the armed forces and outside to secure code books, Enigma machine wheels and other "cribs" to help the code breakers.

The hardest part for me was reading about the fate of the various Polish mathemeticians who pioneered the Enigma work throughout the 1930's, and who were mostly left to perish in tragic circumstances by the French and British, despite being got out of Poland after the German invasion.

After reading Andrew Hodges's biography of Turing I was interested in reading more about how Enigma was cracked. Unfortunately this book is a little short on details. Most of the technical info has been relegated to appendices and I feel that the author didn't really understand the cryptographic techniques used. As a result I know far more about the Enigma itself from Hodges's book than from this book. In fact a recent Nova program on PBS gave more technical details. It's rare to find less detail in a book than a TV programme.

On the other hand I didn't expect the historical material to be interesting - merely a list of dates and U-boat numbers. I was wrong. It makes a fascinating read with all sorts of cloak and dagger exploits. In fact it's probably the most interesting WWII book I have read.

So all in all I highly recommend this book but you need to turn to other sources if you want to understand the technical challenges that faced Turing et al.

In last year's film _U-571_, tribute was paid to those American heroes who were able to grab a Nazi Enigma encryption machine, thereby enabling the allies to break enemy messages and win the war. _U-571_ showed the American heroes capturing Enigma, when in truth it was British heroes who did so, and not just once. Nonetheless, the film did demonstrate the continuing realization of the importance of the cracking of Enigma, the most famous episode of codebreaking in history. The story of the English boffins at Bletchley Park, led by the strange, brilliant, and doomed Alan Turing is indeed one of the great victories of the war.

But it wasn't all mathematicians, primitive computers, and brainpower. _Enigma: The Battle for the Code_ (John Wiley & Sons) by Hugh Sebag-Montefiore tells plenty about the cerebral efforts within Bletchley Park, but expands the story to include the cloak-and-dagger work and military captures of German vessels that were able to bring codebooks, Enigma machines, and encoding wheels into the purview of the cryptographers. The victory over Enigma is a thrilling story that first started being revealed only twenty years ago, and this book helps to describe the difficulties the decoders went through because of the hazards of getting information from the field. And it is a good story, with hair-raising escapes, bureaucratic in-fighting, eccentric characters, and genuine heroism on the high seas.

Some of the spywork was mundane. We owe a lot to Hans Thilo Schmidt, for instance, the German who spied for the French Secret Service, providing keys to the system as early as 1931. Schmidt was, however, no hero; he was simply in it for the money, to pay for vacations and mistresses. He continued to provide information for pay until caught by the Germans in 1943. Captured, he took cyanide, perhaps provided by his family and perhaps allowed by his captors to avoid an embarrassing trial. His story has not been told before, and came from sources previously unavailable to historians.

_Enigma_ gives a chronology of the battle for the codes that demonstrates how vital decryption was in winning the war in the Atlantic. When Bletchley Park could decrypt quickly, information got to the convoys enabling them to avoid U-boats. When the Nazis changed methods of using Enigma, information slowed and ships were lost. The ups and downs of gaining information from spies or from captured ships and using that information to crack messages is well told here. The victory over Enigma is rightly remembered and celebrated. Sebag-Montefiore expands the extent of the victory beyond the Bletchley cerebrations to the mostly unsung heroes who gave the code-crunchers something to work on. The book is full of information, including appendices on details of how the Enigma machine worked and a useful chronology of high points in the Enigma battle. It is a vivid account of the battles at sea and on land that won the code war.