by Alastair Denniston- Code-breaking From Room 40 to Berkeley Street
Sectional records
This because when all is over (a) either we have won or (b) we are defeated.
If (a) we may want to begin again.
If (b) a compromise of our activities will not surprise the victors, should they discover these papers.
In this respect, I blame myself alone for destruction of French naval records which might have been of use today.
Certain Diplomatic sections may be invaluable during negotiations viz. American, S. American, Spanish, Vatican, Turkish, Arabic, Persian, Chinese & Japanese.
If I can disperse these sections in a crisis in the case of trustworthy leaders to unobtrusive unknown private homes with a promise of destruction in the face of danger, these sections could be reassembled and made to function at short notice should it be necessary and should material again become available.
Thus, for example, the American section (Captain Hanly and Miss Curtis) have a little villa in Water Eaton. They could here keep current books and material and rejoin; the Chinese section leader, Colonel Jeffrey, is with Sir Everard Duncombe at Great Brickhill with cellars and security and obviously a country gentleman and nothing more.
Similarly I might find safe homes for the other important sections. Some risk must be accepted. If we are defeated, what extra harm will be done, if we win we keep the stuff in odd places and start again when we are wanted.24
By September 1940, BP’s codebreaking efforts were starting to have real impact on the conduct of the war. Hut 6 broke a key which they called Brown I and was used by the GAF Signals Experimental Regiment.25 An earlier decrypt on 5 June revealed that something called ‘Knickebein’ was being used by German aircraft with special receiving equipment. It was already known that this was the cover name for navigational beams. No.8 Group (Bomber Command) was formed and became responsible for all radio countermeasures. By October, their success forced the Germans to switch to another system, the ‘X Gerãt’, used by the pathfinders of KG 100 to locate and illuminate targets for the main bomber force. Hut 6’s break of Brown I allowed the X Gerãt transmissions to be jammed by the end of 1940. Good liaison was established between Huts 6 and 3 and Assistant Director of Intelligence (Science) in this work. As Birch wrote in his Official History after the war: ‘In 1940 we find only the beginnings of a long story of closely integrated cooperation between operators, log-readers, low and highgrade cryptanalysts, reporting staff and technical intelligence officers that lasted throughout the war and was unique of its kind in the history of British Sigint.’
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To provide contingency against damage to the six fixed Y stations operational at Denmark Hill, Sandridge, Cheadle, Chatham, Flowerdown and Scarborough, Chicksands was selected as a suitable inter-service site and houses at Wavendon were acquired as a back-up to BP. In case of invasion, quarters were found for around 150 GC&CS staff near Market Drayton. The position by the end of September was grim, with buses providing transport not operable, incomplete billeting accommodation, intercept conditions dubious and a lack of an alternative site evident.26 AGD did not believe GC&CS could function if it had to move far from BP. By 13 September, German Naval Section inferred from traffic analysis that everything was in place for an invasion but on the 15th, the danger of immediate invasion had receded. This was confirmed from special intelligence at the end of October.
When Italy came into the war, GC&CS was better prepared because of its focus on Italy and Japan between the wars. However, from September 1940, the Italian components of the three service sections at BP struggled to maintain enough staff as many were seconded to locally-based units at Alexandria, Sarafand and Cairo. Some work in the field on Italian ciphers was supported by GC&CS and some at BP as research activity. Middle East military commands wanted more GC&CS staff, claiming that delays rendered its contribution ‘of academic interest only by the time it is received’.27 These claims were rejected by the heads of the Army and Air sections at BP, Tiltman and Cooper.28
The Italians had made changes to their high-level code books and ciphers in July and added new ones so that by the end of the year, a multiplicity of new ciphers caused a complete blackout. However, in September Knox broke an Italian machine which had been in use during the Spanish Civil War. While traffic was minimal, it included very important intelligence – most dramatically during the Battle of Matapan.29 Middle East Control was having success with the East African cipher, while GC&CS struggled against the main Mediterranean cipher which changed frequently. Thus Middle East control pressed for control over all Italian Sigint work. AGD, however, continued to argue for the model of research at home and exploitation in a combined Middle East bureau. A party from GC&CS consisting of one naval, three military, three RAF and two Foreign Office officials30 left England on 18 July, followed in August by the head of the Italian Military section, F.A. Jacob, and clerical staff. The intention was to set up an inter-service cryptanalytic centre. AGD reported that ‘it is not yet known where they will work in Cairo nor under whose organisation’.31 The three Directors of Intelligence agreed on 29 October that an inter-service cryptographic bureau should be set up under Jacob.32 The so-called W Committee in Cairo accepted the proposal with certain reservations, as the new Combined Bureau Middle East (CBME) was in effect a cryptanalytical bureau, not a Sigint centre. CBME was supposed to be an inter-service cryptanalytic section reporting to a W Committee. As AGD said ‘there is in effect as yet no real inter-service bureau but three components each taking orders from their own Service authorities, Jacob [Lt.-Col Jacob, Director CBME] being allowed to try to co-ordinate their work’.33
While the Italian Naval Signals Intelligence Section was making little progress, according to Clarke, Head of the Italian Naval Section at GC&CS,
it would be a mistake to bring Murray’s [Commander J. Murray, Head of SI] party home. Cryptography has its ups and downs, and a little luck might easily change the situation in a moment. The capture of documents might … create the necessity for a decoding staff there – there has never been a cryptographical staff. There are plenty of minor … jobs for them to tackle now – Fleet codes, reporting codes, mercantile codes, etc. Their efforts are wasted, if they try problems too hard for them.34
While AGD thought that the inter-service Sigint model should be followed in the Middle East, Birch argued in his Official History that while inter-service was a nice principle,
at GC&CS itself, although the Sigint work of all three Services was conducted in one place to very great mutual advantage, inter-service fusion of functioning was limited to the use of analytic machinery and to army-air partnership in the solution of and exploitation of German Army and Air Enigma traffic as a result of the originally fortuitous interception of the GAF traffic by a military Y station and the subsequent artificial segregation of this enterprise from all other Sigint activities, and of its subordination not to War Office and Air Ministry but to SIS.
As early as 1937, the cooperation of Commonwealth Allies had been sought to obtain traffic from commercial telegraphy stations. There was wireless intercept cooperation with the navies of Canada, Australia and New Zealand from around 1925, and DNI Ottawa’s station at Esquimalt, British Columbia became a useful source of commercial intercepts for GC&CS. As well as Esquimalt on the Pacific, Canadian naval Sigint had Y and direction finding stations at Hartlen Point, Nova Scotia, and St. Hubert, Quebec. Australia also wanted to help and considered it ‘desirable to examine the possibility of establishing a nucleus organisation in this country to guard against the contingency of operations in and about Australia and her territories’.35 However, little was achieved for some time. New Zealand established a ‘Combined Intelligence Bureau and Central War Room’ in Wellington in September, and exchanged information with FECB in Singapore. South Africa could do nothing officially for political reasons, but discretely, a chain of direction finding stations at Bloemfontein, Durban, Johannesburg, Komatipoort, Port Elizabeth and Simonstown proved valuable.
Other European allies emerge
d, and the Finnish General Staff offered cooperation with a GC&CS Russian Section and Tiltman obtained from them ‘information, copies of documents and intercepted material of very great value’.36 Just before the French campaign, French Navy and Army cryptanalysts were seconded to GC&CS. However, after the French armistice with Germany on 22 June 1940, they gradually left BP.37
Birch summed up the situation at BP at the end of 1940 as follows:
Dissected thus, G.C. & C.S. as a working organism appears freakish. Its administration was not made easier by the fact that Bletchley Park was at that time the ‘War Station’ of the S.I.S as well. In November 1939, Commander Denniston had appointed Paymaster-Commander A.R. Bradshaw, R.N. (retd.) as ‘General Administrative Officer for the G.C. & C.S.’ component but in October 1940 ‘by direction of the C.S.S., the general administration of the whole War Station was placed under a ‘Joint Management Committee’ (J.M.C.) consisting of Captain W.H.W. Ridley, R.N. (S.I.S.) and Paymaster-Commander A.R. Bradshaw (G.C. & C.S.). The dual control did not function very smoothly or efficiently, and, what with one thing and another, the administration both of work and for maintenance came in for a good deal of criticism.
The case for the defence is fairly obvious: It is easy to be wise after the event; in a succession of emergencies only hand-to-mouth empirical improvisations are possible. With so many Ministries fingering the pie, each proffering a different solution to every problem and demanding different treatment, no uniform pattern was possible. The unforeseeable contingencies of bombing and invasion made long-term and large scale planning impossible. In 16 months the nominal role of G.C. & C.S. had increased fourfold and, if working accommodation and billets were insufficient and bad, morale was never higher (civilian recruits had all volunteered, and war was not yet routine).
However, these weighty considerations do not entirely dispel the impression of a rudderless vessel buffeted about at the mercy of every wave of circumstance. On the one hand, there is considerable negative evidence of the lack of any adequate machinery for government; on the other hand, there seems to have been some confusion between administration in the sense of governing and administration in the sense of providing ancillary services; so that policy appears unduly conditioned to the convenience of the latter. Such, at all events, were the opinions formed, and expressed more bluntly, in the Service Ministries. Signs of a change of outlook on the part of the G.C. & C.S. management are, however, perceptible in a memorable ‘Introductory Remark’ to Commander Denniston’s ‘Report for 1940’ to the Director: ‘In the past we have fitted the work into the huts as they became available. I believe greater efficiency could be obtained by arranging the huts to suit the work.’
AGD’s end-of-year report to Menzies reveals just how busy his organisation had been:
Executive Summary:
I submit herewith a survey of the work of the G.C. & C.S. during 1940, and a report on the position of enemy and neutral ciphers at the beginning of 1941.
I have included a brief resume of the methods of circulation of results to the Departments concerned in case you may wish to make any alterations or expansion.
I have also given details of the staff at present employed on the work, with the estimate from Heads of Sections of necessary increases during 1941.
I have had to ask your sanction for increase of accommodation at the Park during 1940, and it is only my duty to keep you informed of any possible further demands which may have to be made during the coming year.
The increase of staff to meet increase of traffic, and success in tackling new problems, is very closely connected with office accommodation, billeting and transport.
I would suggest that any further building be based on a longterm plan rather than hut-building to accommodate new sections.
In the past we have fitted the work into the huts as they became available. I believe greater efficiency could be obtained by arranging the huts to suit the work.
The ideal (which we can now not attain) would be a star-shaped conclave (to permit expansion) with a D & R (Distribution & Routing) and Teleprinter room in the centre, all interconnects with pneumatic tubes.
The saving of time and staff would well have justified a high initial expenditure.
From the purely cryptographic side of the report certain facts emerge very quickly:
Germans and Russians have taken steps that their diplomatic cyphers shall not be read.
Both these powers have had ample warnings and have profited.
With the introduction, during 1940, of individual tables into our own F.O. service, I am satisfied that at last our own diplomatic authorities have adopted enemy methods and safeguarded our cypher communications.
From a perusal of the reports of our service sections, it seems clear to me that the Naval authorities of the Great Powers pay greater attention to cypher security than their sister services.
Although we employ a large staff of experts on German Naval and Italian Naval work, very few Naval cyphers have become legible since the entry into the war of these powers. French Naval cyphers are legible chiefly because of the capture of the French S/M Narval. We had, therefore, been forced in peace to study the new art of W/T Intelligence or Y Intelligence and to assist in its development. I do not, however, intend to include any notes on this subject in this cryptographic report.
The Far East and Near East, who had hoped perhaps that their security lay in language, have been obliged also to tighten up their cypher methods.
We are nearly keeping pace and obtaining solutions but it is only a matter of time until these Powers too produce methods which may make solution more difficult and irregular.
In 1935 I asked Commander Travis to investigate the possibilities of mechanical aids in our work. He started then, but only in 1940 was he able to achieve very considerable success, as is shown in his report.
I consider this success largely due to Travis’ intimate cooperation with B.T.M. who have given of their best in staff and equipment, and Travis has known how to utilise it. Thousands of hours and hundreds of staff have been saved by these efforts.
This success has forced us to modify our views on the safety of subtractor tables. Every service using general tables must provide an adequate supply to enable more frequent changes, and must institute safeguards against misuse and overuse of their tables.
Were it not for the loyal cooperation of Colonel Tiltman (Head of the Military Section) and Mr. Cooper (Head of the Air Section) I hardly know how this large interservice office could have been run. Tiltman and Cooper both owe loyalty to their Service chiefs. But they have never failed to back our main duty, attack on enemy cyphers. They are well aware that interservice cooperation as it pertains here is the only way of fulfilling the functions for which we are appointed.
Apart from the normal expansion in the various sections as detailed in this report, I have in mind the development, in which all my senior colleagues agree, of a Service Distribution and Reference office on the same lines as the Diplomatic D. and R. of which Smith is the Head.
Decodes of operational value will continue to be teleprinted direct by the Sections as at present. The distribution of typed copies would however be done by this new Section, who would also distribute them among the Sections here, and maintain all the information from this and other sources in a form for easy reference by the Sections.
If it were possible, this Section should be accommodated next to the Diplomatic D. and R.; but this cannot be so on account of our present accommodation.
The new Section must be in a central part of B/P, and I consider that the senior staff should consist of officers from the Intelligence Divisions of the three Services, who should know the requirements of the general staff and a member of G.C. & C.S. who should know the possibilities of cryptography and the needs of cryptographers. It is in no sense an Intelligence Office except in so far as the needs of the Service Sections of G.C. & C.S. require a centralised Intelligence and File of enemy telegrams which would ass
ist their work.
This Section would have a threefold purpose:
It should be of great assistance to the cryptographers to have a central office to which they could refer for information which may help them in their own problems, or when they can search among contemporary decodes for cribs.
It will meet a need sometimes expressed by the Intelligence Department of the Services for a central office, where all decodes are available for scrutiny by a member of their own Department, and so provide against the loss of anything which might be of interest to them.
It will relieve from the cryptographic sections the responsibility for the distribution of decodes and thus give them more time for their production.38
AGD was also keen to establish with Menzies, as he had done with Sinclair, the importance of maintaining a unified cryptography centre as evidenced by this note from him to Menzies on 22 December 1940:
The Romer Committee in 1919 founded the G.C. & C.S. and directed that all cryptography should be centred there, the Army and Navy to collect the necessary W/T material, of which there was then very little. The G.C. & C.S. was also entrusted with the security of British Cyphers and their construction.
For the first few years W/T interception was kept going with some difficulty owing to the urgent necessity for economy. The R.A.F. came into the picture in 1927.
For cryptography, a military section was started in the G.C. & C.S. in 1932 [?] so that a party would be available for service in the field, and an Air Section was started in 1936. A Far East Joint Bureau was instituted at Hong Kong, administered by the Navy and the Head of the Bureau is paid for by the F.O. A Middle East Joint Bureau has only just come into being.
As you know the fighting services, especially the Army and Air, have been served with intelligence far beyond their expectations during operations in Norway and France and now at Home. The story of this is of some interest in pointing out the benefits of centralisation.
