root@ucsfcca.UUCP (Computer Center) (03/17/86)
Enigma Decryption & Bombes
Welchman pp. 295-309 gives considerable detail on the logic and
construction of the bombes in addition to much methodological
discussion in the text.
Garlinski, pp. 233-249 gives detail on the Enigma construction
and cryptanalysis, presumably the methods used by the Polish
cryptologists.
He includes a picture of a bombe facing p. 196 and of Colossus
four pages later. A differently cropped example of what
appears to be the same photograph appears in Lewin.
Coventry Raid
Winterbotham, p. 60 explicitly states that the name Coventry appeared
spelled out within a message intercepted about 3 p.m. on 14 Nov and
that this was exceptional and that he had himself passed this direct to
Churchill's personal secretary.
Jones, p. 150 states that Winterbotham's assertion (referred to as
"some accounts") was "effectively disposed of" by a review in The
Times Literary Supplement, 28 May 76 by Sir David Hunt, Churchill's
onetime secretary, based on statements of Sir John Colville who was
on duty at 10 Downing St. on the *night* in question.
Lewin, pp. 99-103, gives a credible account along with some hints
of what occurred. The regular staff was dispersed that afternoon
on Churchill's orders since he had gone out of the city to a
weekend retreat. The atmosphere is described as resembling an
ant-heap (and passing mention is made that more than one person
held title as Private Secretary to Churchill).
He concludes with the dry observation:
The log book for No. 10 disappeared, unfortunately,
after the war.
Hinsley et al, p. 336 asserts
Group Captain Winterbotham is right to say that
Coventry was not identified as the target until
about 3 pm on 14 November but wrong to suggest
that counter-measures were limited by the need
to safeguard the source; and wrong in claiming
that the word Coventry was spelt out in an int-
ercepted signal.
A fairly straightforward scenario now emerges. It seems possible
that Winterbotham received and forwarded exactly the message he
indicated. The message was received and logged at No. 10 by one
of several secretaries who did not realize it's significance at
the time and it did not reach Churchill. When it was realized
what had happened either the person who received the message
acting alone destroyed it or the bureaucracy closed ranks to
protect itself and destroyed it and ultimately even the record
of a message.
Of course, once we admit the possibility -- even probability --
of a cover-up then it seems worth considering that Churchill
did receive the message, recognized that it was too late for
any really extraordinary measures in the face of the
hazards of alternate targets, diversions, etc.
and that he or his staff felt it worth while to try to
blunt criticisms eleswhere in the government.
Thus, by the time of preparation of Hinsley's official history
the critical original sources had disappeared and they are
reduced to thirty plus year old recollections as in
Mr P G lucas indeed thinks that on the afternoon
of the raid a low-grade GAF signal was intercepted ...
and
If their recollection is perfect this must mean
either that the Prime Minister ... never got the second
warning, received about 3 pm to the effect that
Coventry had been identified by the beams;
(the German radio guidance beams for the attacking aircraft)
which contradicts Jones attempt to discredit Winterbotham.
Of course, until the beams were actually started up to guide the
planes intelligence about them was from intercepts of Enigma
encrypted signals, i.e. Ultra.
It was this beam intelligence which was R. V. Jones
particular concern. Jones asserts that as late as half past five
their people were only "fairly sure that the target was somewhere
in the midlands, and his problem was to decide which beam
was which" which doesn't jell with Hinsley.
Calvocoressi, p. 75, says
It has been alleged that we knew in advance from Ultra
that Coventry was to be attacked that night and that,
in order to avoid compromising the source Churchill
refused to allow action to be taken to minimize the
death and destruction. None of this is true.
and labels it a "false story" that gave "this tragedy a second
notoriety" thereby asserting a disapproval of such a decision and
showing reason for a cover up.
Where does all this leave us? Well Winterbotham broke the story
and thereby aroused the envy and subsequent enmity of a lot of
people for getting into print first after the lifting of the
official ban on publication. Obviously some of these people did
or would have disapproved of a decision such as Churchill was
alleged to have made and wanted to disassociate it from the
the government and war effort in which they participated.
Ultra to the Eastern Front
Garlinski, pp. 119-144, in a chapter entitled "Secret Despatches
Flow Towards Moscow" discusses at length the possible techniques,
and their motivations, for transmission of Ultra derived material
to the Soviet Union. He quotes there from Fitzgibbon (see below)
and alludes to A. Friendly on the same point but I don't have the
Friendly article available. He also states that H. R. Kurz, whose
book was published before the Ultra revelations occurred, has now
expressed in person the view that Ultra derived material was passed
through the `Lucy Ring.'
Fitzgibbon, p. 277 says
Since the Russians would not accept military
intelligence from any but their own sources,
Ultra and much else was `fed' to the Russians
via the `Lucy Ring' and undoubtedly with the
help of Swiss intelligence.
The "much else" is clarified on pp. 285-6
The regular situation reports from the Japanese
military attache and from his ambassador in
Berlin to Tokyo were of immense value,
particularly to the Russians once they had
been passed through the Lucy Ring.
Bibliography (Note that copyright dates are used instead of publication
dates since they better approximate the vintage of the information):
"Confessions of a Code_breaker", The Washington Post, A. Friendly,
27 Oct 1974
The Enigma War, J. Garlinski, Charles Scribner's Sons, New York,
(C) 1979
The Hut Six Story, G. Welchman, McGraw-Hill, New York, (c) 1982
Nachrichtenzentrum Schweiz, H. R. Kurz, Frauenfeld and Stuttgart, 1972
Top Secret Ultra, P. Calvocoressi, Pantheon Books, New York (C) 1980
The Ultra Secret, F. W Winterbotham, Harper & Row (C) 1974
The Wizard War, R. V. Jones, Coward, McCann, & Geohagen Inc. New York
(C) 1978, British Title: Most Secret War
Ultra Goes to War, R. Lewin, McGraw-Hill, New York, (C) 1978
British Intelligence in the Second World War, Volume 1, F. H. Hinsley
et al, Cambridge University Press, New York, (C) 1979
Secret Intelligence in the Twentieth Century, C. Fitzgibbon,
Stein and Day, New York, (C) 1976