20 March 2013
NSA Assesses Winterbotham's "The Ultra Secret"
NSA Cryptolog 15, VOL. II, NO. 12 DECEMBER 1975
NATIONAL SECURITY AGENCY
FORT GEROGE G. MEADE, MARYLAND
WINTERBOTHAM'S "THE ULTRA SECRET":
A PERSONAL COMMENT Brigadier John H. Tiltman
WEAPON THAT HELPED DEFEAT NAZIS P. W. Filby
MUM'S STILL THE WORD! [redacted]
THIS DOCUMENT CONTAINS CODEWORD MATERIAL
Declassified and Approved for Release by NSA on 10-11-2012 pursuant to E.O.
MDR Case # 54778
WINTERBOTHAM'S "THE ULTRA SECRET"
The following three articles deal in various ways with the publicity given
in the British and American press and on television to F. W. Winterbotham's
book "The Ultra Secret." The first article, by Brigadier John H. Tiltman,
deals with the accuracy of the statements in the book and the degree of harm
done by them. The second article, by P. W. Filby, is a review of the book
as assessed by a member of the team of specialists who worked the German
diplomatic problem. The third article, by [redacted] M542, a word of advice
to those who might now be tempted to tell everything they know.
A PERSONAL COMMENT
By Brigadier John H. Tiltman, P1
When Winterbotham's book was first published late in 1974 in England, some
members of NSA who had served at Bletchley Park during World War II, on reading
early reviews, assumed that it was officially authorised. This was definitely
not the case. Its publication was strenuously opposed by British responsible
authorities, who took legal advice on the probable consequences of prosecuting
the author under the British Official Secrets Act. They were advised that
prosecution could not be effective without the case going to court and evidence
produced that British national security had been damaged by the book's
publication with consequent public disclosure of more current intelligence
activities. They therefore decided that legal action would probably do more
harm than good.
Another and perhaps a decisive factor making prosecution unlikely to succeed
was the publication in France in 1973 of Bertrand's book Enigma, ou La
Plus Grande Enigme de la Guerre 1939-1945. This revealed for the first
time the fact of an analytic success against the Enigma and was decisive
in the discussions between Deputy Director NSA and Director GCHQ on the matter
of whether to attempt to restrain Winterbotham and his publisher.
I am not alone in believing that an early official public description (perhaps
a joint US-UK statement) of the basic facts of the wartime exploitation of
the intelligence derived from the solution of the Enigma keys might have
mitigated the damage done to security. Perhaps this could have been strengthened
by a further
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statement that the revelation of technical details of the methods of solution
would be resisted indefinitely. I realise however that there must be other
valid arguments which persuaded the responsible authorities not to take such
I myself took no part in the solution of Enigma keys in Huts 6 and 8, nor
in its exploitation in Hut 3, but I am, I believe, the only person around
who was on the directorate level at Bletchley Park during the war and had
a hand in many of the policy decisions made regarding the production and
use of the intelligence derived.
The book is poorly written and very inaccurate in some areas where I know
the facts. The references to the early history of Enigma solution and to
the activities of the staff of Hut 6 (who performed the cryptanalytic part
of the enterprise) are hopelessly wrong. It is difficult to understand how
the author who had considerable responsibilities for the organisation and
distribution of Enigma intelligence could have been so completely ignorant
of the technical side of the operation. He doesn't know the difference between
the Enigma (a rotor machine), other German ciphers, the Japanese high-grade
diplomatic machine (the "Purple," a totally different kind of machine), and
the Japanese Fleet general cipher (a codebook and additive hand system).
His remarks about the "Bronze Goddess" appear to be a complete invention.
Some people gather the impression when they read the book that the author
greatly magnifies his own part in the winning of the war. I give an example
from my own experience. To quote some passages, "It was at this point that
Menzies told me he had decided to hand over my shadow OKW in Hut 3 to the
General Administration at Bletchley. One never knew where one stood with
Menzies. He softened the pill by confirming me as his deputy ... " (p. 87).
"Despite the loss of my personal control of Hut 3 and the shadow OKW, I still
had direct access to it when required. I was never told by Menzies the real
reasons for the takeover ... "(p. 92). The facts are that I reported to the
Director of Military Intelligence at the War Office, that Curtis, the War
Office representative in Hut 3, in conjunction with Humphries, the corresponding
Air Force representative, had on two separate occasions gone behind my back
to recommend reorganisation of Hut 3 under their own more direct control.
In consequence, a SIGINT Board meeting was called with General Menzies in
the chair and consisting of the three Service Directors of Intelligence and
Director GCHQ. At this meeting it was decided to withdraw Humphries, Curtis,
and the naval representative.
I knew Winterbotham slightly and flew with him to Paris on the occasion of
one of my official visits to France in 1940. His outstanding achievement
was the establishment of SLUs (special liaison units) for the dissemination
of ULTRA to commanders in the field. I have no reason to doubt that he records
this faithfully. He gives rise to feelings of dscomfort, however, when he
describes his relations with the more high-ranking recipients of his wares.
It appears that Montgomery must have treated him with less courtesy than
others and consequently he feels sure he himself could have fought Montgomery's
battles far more efficiently!
In view of its general inaccuracy, especially when touching on technical
matters, I believe the book, taken by itself, does no harm. This cannot be
said for the side effects it touched off. The first review I read was in
the Washington Post by Al Friendly, who himself served in Hut 3. He
headlines his review "Confessions of a Codebreaker." He gives the impression
that for a great part of the war every telegraphic order issued by Hitler
was currently on the desk of the Prime Minister and concerned Allied commanders.
This is simply not true. Such a picture takes no account of the many difficulties
of the operation, the decisions to be taken on insufficient evidence as to
priorities of attack on some keys to the exclusion of others, the many failures
and delays, the early misunderstanding as to the real meaning of messages,
etc. The general success of the project was as much a triumph of organisation
of the large-scale attack as of the ingenuity and persistence of the
cryptanalysts, especially the mathematicians.
Perhaps the most objectionable of the reviews was a long article in one of
the London Sunday newspapers by Peter Calvocoressi. He was an important figure
in Hut 3, presumably recruited by Winterbotham. He is now, I believe, managing
director of Penguin Books and was the joint author of a distinguished history
of World War II. His article is an extremely well-written description of
life in Hut 3, but he has gone further than anyone else in including a photograph
of the German Service Enigma and in mentioning the Bombe. I believe this
was the first time a picture of the service Enigma appeared in public print.
Not even Bertrand in his book Enigma gives a photograph of the machine.
I am quite unable to understand Calvocoressi's arrogant assumption that he
can say what he likes in public now that Winterbotham's book has appeared.
I hold the view that everyone who worked in Bletchley Park is still under
a moral obligation not to disclose secrets not previously published without
official permission and, I would have thought, is aware of this obligation.
Many of us were nervous of what David Kahn would have to say when his turn
came to review the book. When his review did appear in the New York Review
of Books, it was surprisingly mild and harmless. He, of course, is in
a different category. Not ever having been a part of
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any Government agency, he cannot be regarded as subject to the same restrictions.
Other reviewers have been influential journalists who have taken the tone
that the book has revealed the operations of World War II in a new light,
that history will have to be rewritten, that the British have told only part
of the story and that they will have to tell the rest. I do not know whether
we have heard the last of this attitude.
Something has to be said about the paragraphs on page 14 of the book dealing
with personalities. Winterbotham mentions the mathematicians Alexander, Babbage,
Welchman, and Milner Barry, but doesn't seem to have heard of Turing, who
is generally regarded as the leading genius of the methods of solution of
the Enigma in its various forms. He says that "it was generally accepted
that of our own backroom boys 'Dilly' Knox was the mastermind behind the
Enigma affair." I do not agree with this at all, though I am aware that he
was in general charge of the analysis of the machine before the war and long
before the British had any success in solution. Incidentally, Winterbotham
seems to confuse Knox with Foss, who fits much better into the physical
description in the book and who had some influence mbes became available.
In his casual remarks about me, Winterbotham is somewhere near the truth:
he says I had been borrowed from the Army. So I was -- 20 years earlier!
Of Josh Cooper he says he was "another brilliant mathematician." Josh wasn't
a mathematician at all -- he was a very fine linguist. For no known reason,
Winterbotham mentions Dick Pritchard. He was a regular Army officer who had
been with me for 8 or 9 years, before the war, but he had nothing whatever
to do with the solution of the Enigma.
I think it quite likely that all this does no harm at all, but we cannot
by any means be certain of this. Therefore, we have to continue to try to
withhold further disclosures, particularly on technical methods of solution.
Briigadier Tiltman was Deputy Director and Chief Cryptographer, GCHQ, from
1941 to 1946. Since 1964 he has been working at NSA, Fort Meade. He is a
Commander, Order of St. Michael and St. George; Commander, Order of the British
Empire; and Distinguished Member, CMI.
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ULTRA WAS SECRET WEAPON THAT HELPED DEFEAT NAZIS
By P. W. Filby
Shortly after the outbreak of World War II, the British Government acquired
a stately home in a small town called Bletchley, a town renowned only for
its railway junction and nearby brickyards. For the next few months civilians
and servicemen and women arrived in ever increasing numbers, and hardly a
house in Bletchley escaped billeting. The citizens wondered at the motley
crowd, raffishly dressed for the most part, often absent-minded and all having
a studious air about them.
High iron fences were erected round the home known as Bletchley Park and
armed Army guards were on duty at all times. The locals had to get used to
comings and goings of their lodgers at all hours, and having taken in civilians
they would suddenly see them emerge in full regalia as officers of the three
services, especially when they made trips to London.
Many guesses were hazarded but the only thing that could be said was that
it was a secret department -- and the secret was well kept, so well that
it is not until now, thirty years later, that the Bletchley people and the
world will know that the many thousands of people at the "Park" were working
in enemy codes and ciphers.
Group Captain Winterbotham has taken advantage of the "30-year rule" to describe
the success of one group, "Hut 3." It is an absorbing story, and although
the chief defect is that Winterbotham was not a codebreaker and therefore
makes several wrong assertions, the book is one of outstanding interest,
and readers will marvel at the war's greatest secret and how it was kept
Just before the outbreak of World War II the British had obtained by various
means a complex machine known as "Enigma" which was being used for the encoding
of the most secret and important German armed forces communications . After
a prodigious effort the British cryptographers of "Hut 3" managed to break
this machine and later built what might well have been the first computer,
so that the communications could be read immediately upon receipt.
To everyone's surprise, the Germans continued to use this machine throughout
the war and thus most plans made by Hitler and his High Command were known
to the British (and later, the Americans also) at the same time as the German
Radio operators in remote, lonely locations intercepted the messages, which
were rushed to
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Bletchley, often by motorcycle until more sophisticated methods were evolved,
and were promptly decoded and passed to the appropriate commands. The
intelligence was code-named "Ultra."
Astonishingly, there is nothing in captured German documents to suggest that
anyone sus pected that the most secret cypher code was being read throughout
the war. Much of the credit for this were the rules laid down by Winterbotham
for the "need to know."
For instance, the Russians were never told of it, and the many free forces
(French, Dutch, etc.) were not let in on the secret. Winterbotham toured
British and American commands, lecturing users on this intelligence and warning
them care had to be taken on how the information could be used.
For instance, although the presence of an enemy force might be given in detail
by Ultra, to bomb it immediately would cause the Germans to wonder how the
enemy knew of this force, so reconnaissance planes had to be used so that
the Germans would suspect that they had been spotted from the air.
Unhappily, it was not unusual for holders of the German plans to have to
forgo using them for fear of compromising the cypher break. One such occasion
was the bombing of poor Coventry; enemy plans were known beforehand, but
to defend the city would have aroused German suspicions. Although attempts
to defend were made, the populace was not warned in advance. At that time
it was not known whether German spies were working among the British.
But the information was used with telling effect in the Battle of Britain,
when the Air Force knew exactly the direction and the force to be employed
in each attack. It is probable that Ultra did much to save Britain in those
dark days. Everyone knew the Air Force could not withstand these onslaughts
for long, but Ultra allowed them breathing space by parceling out the slender
defense forces where needed most.
Ultra played a particularly distinguished part in the North African campaign,
where Montgomery was informed of Rommel's disposition of his forces and the
extent of his supplies. Ultra also enabled supplies across the Mediterranean
Sea to be sunk en route. Montgomery's face should be red, since he claimed
verbally and in his books that he planned his battle order, but he acquired
the record of invincibility only through his use of the information given
With the British losing thousands of tons of shipping weekly, the decoding
of the German Navy's messages provided a welcome respite, and from 1943 the
losses were significantly reduced since the disposition of the U-boats was
One wonders now just how the Normandy landing would have worked out without
Ultra. Since decoded messages told of the German belief that the attack would
come from the narrow Pas de Calais, General Patton arrived with a phantom
army to give the impression the landing would indeed be tried there. Consequently
Rundstedt and a vast army were kept there, reducing the defenses in Normandy.
Ultra's strength was also shown when, in the Battle of the Bulge, the Germans
relied on telephone rather than radio communications, and many lives were
lost because the Allies could 1earn nothing of the German plans and intentions.
These and other exciting stories are related in this absorbing book. It suffers
perhaps because Winterbotham was a "go-between" rather than one of the
codebreakers, and thus credit is not given to the mathematicians and linguists
who worked long hours in stuffy rooms where, because of blackout precautions,
fresh air seldom penetrated the smoke-filled atmosphere.
Tribute, must also have been paid to those radio operators, straining their
ears when static and other conditions meant a missed group and maybe an important
one at that, when the operator could not ask for a repeat -- these were the
real heroes of one of the outstanding accomplishments of the war .
One amusing tailpiece to the whole affair is the effect it will have on those
whose memoirs have already been written. Many should now be rewritten; if
Ultra did not actually win the war it will cause historians to revise what
has been written thus far. Books such as "D-Day" are exciting reading, but
the present work must be included in all war hiptory collections from now
on, since it will affect all war histories in varying ways.
Winterbotham is rightly proud of Bletchley's achievement, but he tends to
forget that information, needs acting upon; it needs good generals and above
all a great Air Force, Army, and Navy. Fortunately the Allies had these too,
and though Ultra was one of the most important contributions to the victory,
Winterbotham perhaps overrates it a little.
Sir John Masterman's book, "The Double-Cross System in the War of 1939-1945"
(reviewed in these columns February 12, 1972) describes how captured spies
were "turned around" and also contributed to the downfall of Germany. There
were other great coups but UItra and Double Cross must rank very high in
the defeat of the Nazis.
P. W. Filby, in addition to his SIGINT experience at Bletchley Park and GCHQ,
is an "honorary NSA-er by marriage" (his wife is CLA President and CRYPTOLOG's
SRA Editor Vera R. Filby). Mr. Filby is the current Director of the Maryland
Historial Society, Baltimore, Maryland. The preceding review is reprinted
in entirety from the Baltimore Evening Sun, June 10, 1975.
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MUM'S STILL THE WORD!
By [REDACTED] M542
Many people make their work and the organization they work for an extension
of their own egos, especially when the organization is performing a vital
service to society. For most people, one of the most compelling motivations
on the job is the quest for approval by their peers and supervisors. But
we NSAers are not like "most people." True, we have always been able to rely
on peer and supervisory approval, but we have never been able to derive ego
gratification from identifying with NSA -- historically, both the Agency
itself and our specific jobs here have been obscured from public notice.
Lately, however, the curtain cloaking our activities has been lifted slightly.
Winterbotham's book The Ultra Secret and the follow-on revelations
in the CBS television program, "Sixty Minutes, " have provided the public
with glimpses of the vital role that cryptology plays in protecting our nation's
security. Certainly, all of us must feel a sense of pride, and perhaps indulge
our egos a bit, to see our Agency's vital function finally made known to
the public. It's a very seductive thing. We plug along for years without
public recognition. We strive constantly to overcome the natural urge to
discuss our work with non-NSA friends, particularly when that work involves
events taking place on the world stage. Then, suddenly, there's our organization,
our work -- us! --on the television screen, the front page of the newspaper,
the public bookshelf. How easy it is to feel proud about finally getting
public recognition. But that initial feeling of pride and personal gratification
is soon outweighed by the disquieting realization that someone has talked,
someone has betrayed our tradition of keeping our mouths shut.
The fact that such revelations do not always compromise sensitive information,
as in the case of The Ultra Secret and the TV follow-on, does not
diminish our feelings of dismay. That precious shell of anonymity -- so carefully
maintained over the years -- has been cracked. One can only expect that others
will rush forth to give their versions of past events and open that crack
That our cryptologic operations are discussed at all in the public media,
no matter how many decades have elapsed, is the primary concern here.
Journalistic appetite begets appetite and, once titillated by the morsels
served up by disclosures such as those in Winterbotham's book, it tends to
become ravenous for the whole pot. Those who were associated with the cryptologic
effort in the past -- and the numbers are prodigious -- as well as those
currently involved, are presented with a psychological cop-out to indulge
thelr ego [redacted] talk about their work. After all, everyone else is doing
it. Thus, revelation begets revelation.
The publication of The Ultra Secret, however innocuous its specific
revelations, can only be viewed with foreboding. It can only hasten the dropping
of the next shoe. And when that shoe drops, we NSAers should remember, "Mum's
still the word!"
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