The Prime Minister's Visit to Hut 7

The Prime Minister, Winston Churchill, visited Bletchley Park on Saturday 6 September 1941, on his way to Ditchley Park, where he would stay overnight. There are a couple of more or less plausible accounts of what happened during the visit, but his visit to Hut 7 is not one of the better known. 

Hut 7 was located north of Huts A and B, and west of Hut C, and was built early in 1940, to be occupied by the staff, led by Frederick Freeborn, who transferred there from the British Tabulating Machine Company at Letchworth and their equipment (often referred to as Hollerith machines) Hut 7 was responsible for the bulk of information processing at Bletchley Park, at its peak getting through two million punched cards each week.

I imagine that Hut 7 was chosen partly because of the number of machines it contained, partly because they could be used theatrically to impress the PM, and partly because each of the functions carried out on them could be explained to him in language he would understand, whereas, if he had been taken to see the Bombes, it would have been much harder to explain what was happening.

He would see how a message header and (say) the first ten groups of the message were punched onto cards, then see how a couple of thousand messages could be sorted: into date and time order, perhaps, or by recipient. He could see how a cipher group could be followed through several messages, and how cards could be duplicated if they were valuable as references.

All of this would be to impress upon the PM that the seemingly fantastic resources BP was requesting were not for some sort of vanity project, but rather for the machine age's version of the Room 40 he had been responsible for when it first broke into German naval codes early in November 1914.

The value of the visit came a few weeks' later when four rather naïve cryptanalysts, seeing that the holdups and shortages Bletchley Park was facing were significantly reducing the organisation's intelligence productivity, wrote to the Prime Minister asking him to unlock the delivery of resources. His answer was an instruction to his senior aides, General Ismay and Sir Edward Bridges, to 'make sure they have all they want on extreme priority and report to me that this has been done'.

Many years later Ronald Whelan MBE, one of two brothers Freeborn had brought with him to Bletchley Park in 1940 from Letchworth, remembered the visit in a memoir (TNA HW 25/22) of the work of Hut 7.

'The visit of Winston Churchill

By the time of Churchill's visit to Bletchley Park Hut 7 had become a commodious erection as compared with the modest Hut in which we had started our activities. Being a wooden structure it had been comparatively easy for workmen to tear down walls and partitions, and to tack on extensions, not once but several times, until eventually for a time we had ample accommodation for machines and operators. With such a stage to hand, Freeborn, who apart from his very high technical and administrative abilities was always a showman and an opportunist, planned a memorable demonstration of the use of Hollerith equipment in Bletchley Park on the occasion of Churchill's visit to Hut 7.

Freeborn's secretary, Miss Ellen Ford and I were waiting with Freeborn by the entrance door when Churchill strode down the path towards us, followed by three no-nonsense looking men, who were obviously his bodyguard. As Churchill entered the hut his bodyguards attempted to follow, but Churchill rounded on them and in a voice which would have done credit to that of the great huge bear, rasped "Not you", causing than to stop dead in their tracks.

On entering the Machine Room area on his exit from the Key Punching Room, the visitor was presented with a scene of intense activity. There were about 45 machine operators in action and as many or more than that number of machines. Then all the machines were halted at the same instant, and in the complete silence which followed an Introductory explanation was given to the visitor as the party stood on the threshold of the area. Then as he was conducted towards a group of twelve or more Sorters, all these machines started into action at the same moment. They were allowed to run only for a short time, and all came to rest as one, so that their function and application could be explained without distraction.

Moving from the Sorters to the Reproducers the same arrangement held; all in action on his approach, but at rest for an explanation to be given by Freeborn, the same arrangements applying for each of our various equipments.

At the conclusion of the demonstration all machines were brought into action as the visitor was conducted to the exit, but all brought to rest as he paused on the threshold as he made his farewells. But on reaching the door he turned back, first to stub out his cigar in a nearby ashtray, and then to turn to Miss Ford, to shake her hand and bid her Goodbye.

Miss Ford had a dazed look as she stared at the hand that the great man had held, then she took up the cigar butt and said it was something she would always treasure.'

Visas, Passports, Nationality ...

This post has nothing to do with Sigint history, but arises from a discussion a few of us were having about nationality on Twitter. We had established that there is no right for a British citizen to a passport, nor for a foreign national to a visa to entry the UK. We also discussed the consequences of the Naturalization Act 1870 by which women, on marriage, took on the nationality of their husband 

Looking at documents dating from the 30s and 40s, what strikes me is the fact that decisions are taken by relatively junior members of staff, in a haphazard or arbitrary manner. For example, this report is from the Security Control Officer at Shoreham Airport, and is dated 4 November 1939:

'The below mentioned Alien arrived at this Control 4/11/39 by KLM plane from Amsterdam.

SALZMANN, Paul Von             Nationality: German Jew

Passport No 1296, issued 18/4/39 London

Visa No 10806, issued 2/11/39 Copenhagen

Born 21/8/18 at Berlin

Address 26 Nottingham Place, London W1

Salzmann arrived in UK July 1933 and studied at several places, the last being the South Western Agriculture College, Wye. He left England 26 June 1939 for Denmark for a holiday and there expected to join his parents who were coming from Germany. The parents were unable to leave Germany and Salzmann was told by the Danish police to leave Denmark. He stated that he had come here because he does not want to be sent to Germany. He was refused permission to land as he has no money.' (KV 2/914)

There is a lot to unpack here. A 21 year old German, resident in the UK for several years since he was 14 years old had gone to Denmark and was stranded there by the outbreak of war. The Passport Control Officer in Copenhagen (acting as PCO and not as the Head of the SIS Station) granted him a visa without reference to London as Salzmann was a "returning resident". (Ironically his father, who had left the UK precipitously early in August 1939 was a German spy but that's not the point at issue here.) He was met by his sister, who worked at the Japanese Embassy in London and who said that she would provide for him, but the Security Control Officer took it upon himself to refuse entry to the UK and had him placed on a KLM plane to Amsterdam the next day, in spite of Salzmann's claiming accurately to be half Jewish (though his passport had no prominent "J") and was of an age to join the German Armed Forces if returned to Germany.

His sister, Elsbeth, was by now Mrs MacQueen. She had married a British Subject, and had acquired British nationality and a British passport. She would be interned in 1940 (quite properly) but at this stage looked to be somebody whose husband had left her, and whose parents had left the country, and who was working to keep body and soul together.

She had applied for Naturalisation two years earlier, and the Home Office file contains a minute dated 15 November 1937, in which the official dealing with the query suggests not allowing the application yet, even though she was eligible.

'According to Central Register particulars, Miss Salzmann arrived here in July 1930. She was 21 years old last June and desires to apply for naturalisation. She is a student at London University.

Her parents came to this country a few months before she did, the father being a German.

Both on the grounds that there is no reason to make this girl of a different nationality from her parents and because of her "student" status, I think she should be discouraged from applying although she is in fact eligible by residence to do so and there appear to be no "conditions" attached to her residence.

? Say that on the information before him the Secretary of State would not be prepared to naturalise her and therefore advises that she defers an application for a certificate of naturalisation until, if she remains in this country, her studies are completed.'

The "?" is the official's recommendation and so was subject to internal Home Office discussion, if it hadn't been accepted by all. From a 2022 perspective, it is unthinkable that the application of somebody eligible could be turned down on what looks like a whim.

Gustav Lachmann was a German aeronautical engineer working for Handley Page. He had married an English widow in Japan. In such a sensitive position he had been subject to MI5 enquiries:

'His wife is registered: LACHMANN, Evelyn Wyatt, German, formerly British, born 13/11/97 in Kobe. Former name HAIGH, British, changed to Lachmann, German, by marriage on 29/12/26 in Tokyo. Was GILL, British, by parentage, though born in Japan, father British. Changed to HAIGH, British, by marriage on 19/11/17 in Tokyo. Husband, William, died in September 1923 in Japan. Arrived in the UK 11/11/29 from 10/17 Fukuyoshi Chi, Akaoka, Tokyo. Holds German passport 401 issued 29/12/26 in Tokyo, and registration Certificate 420043 issued 10/1/30 by Bow Street, Serial EZ.172066.' (KV 2/2733 7 February 1930)

This says everything you need to know about the effect on her nationality of a woman marrying a foreigner.

He was in interned on 3 September 1939. Superintendent Herbert Simmons of the East Sussex Constabulary reported:

'… in consequence of instructions from the Special Branch, Metropolitan Police … I arrived at Heydown Farm, Heathfield, where I saw Lachmann, who I immediately arrested.

He was staying at the Farm in company with his wife, two-step-daughters and a maid. He told me that he had arrived there on the 1st September 1939 … Arrangements were made by Lachmann for his family to remain at "Heydown Farm".' (KV 2/2734 3 September 1939)

His wife and children weren't on any list so they were allowed to continue living their normal lives. Lachmann was interned until late in the war, but resumed – in fact never left – employment with Handley Page and on 24 February 1949 obtained a Certificate of Naturalisation, which meant that his wife therefore becomes British by marriage: but not his children. At least one had to apply for naturalisation (KV 2/2735):

'Application for a certificate of naturalisation referred to MI5 by Home Office.

Name: Evelyn Leopldine Lachmann

Address: 49 Weymouth Street, London SW1

Occupation: Radiographer MSR

DOB: 6 December 1927

POB: Tokyo, Japan

Nationality: German'

 Finally, an item from Guy Liddell's diaries (KV 4/185 15 October 1939): a sad story. It might need a trigger warning, as the attitudes underlying the piece are deeply of their time (as is the archness of its language). But equally important, and, I suggest, as deeply of its time, is the Legal Adviser's concern that a young woman is about to do something catastrophically dangerous to herself, and must be stopped.

'A fine legal point has arisen on the application by Miss Phyllis Dalrymple for a permit to travel to Yugoslavia where she intends to marry a German, Alois Brasch, and return with him to his native town of Gratz. This matter was submitted to the Legal Section who replied in the following terms:

 "It is abundantly true that for the purposes of the Trading with the Enemy Act a person shall be deemed to have traded with the enemy:  'if he (and by the blessed Interpretation Act 1889 words importing the masculine gender shall include females) has had any commercial, financial or other intercourse with, or for the benefit of an enemy.' It may be assumed, I fancy, that Miss Dalrymple is intending to have intercourse with an enemy. That in all conscience should be enough. We need not delve into the difficult problem as to whether it would be for the benefit of the particular enemy, who may indeed be pathetically unfit, that Miss Dalrymple should have intercourse with him. Speculation would not be uninteresting on the basis of the particulars supplied on Form P. in respect of the Irish birth, hazel eyes, and dark blonde hair of the young lady, but let it pass! No man who cared anything for the melody of words will be pleased by the name of the individual to whose address Miss Dalrymple desires to proceed, see form P. para 8. A terrifying aspect of this proposed course of conduct is that it may indeed be perilously near to High Treason. I will find out tomorrow. Meanwhile she should not be allowed to leave."'

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Need to Know and Action-On

 

I don't think anybody could disagree with the notion that secret intelligence should only be available to those who need to know. The devil is in the detail:

The strict application of the "need to know" principle from early 1940 onwards was designed to protect the Enigma secret. 'C' was obsessive about the need to protect the fact that the machine the Germans trusted so much that it became their work-horse for encryption had been broken. (In the last LSIB meeting he attended on 1 July 1952 he said that that 'he was convinced that it was only by the most rigid imposition of security that we had won the last war' (Liddell's diaries KV 4/474)).

"Need to know" was imposed inside Bletchley Park as well as outside. Henry Hayward, the Senior Security Officer used to lecture new entrants and impress upon them that 'Secrets which you do not need to know are an unnecessary burden and someone else's secret is never quite so secret as one's own' (de Grey HW 43/78). Staff were discouraged from discussing the work of their section with colleagues from other sections.

In fact, this did not suit the way a Sigint organisation needs to work. It led people to believe that because intelligence derived from cryptanalysis needed a greater level of protection than other intelligence, decrypted material was more important, more valuable, than the rest. The reductio ad absurdam of this position came when the section dealing with German experimental weapons could not get cover of the Luftwaffe nets which produced the intelligence on the development of V-1s and V-2s because it came from plaintext messages and operator chat (HW 43/82 Section K). It also inhibited the sharing of information between huts (except at the most senior level) even though Enigma usage was common across all elements of German forces. Although the area is under-researched, I think it likely that over-rigorous application of "need-to-know" at least contributed to the long delay between it being clear from decrypted material that the Germans were reading to codes in use in the North Atlantic and their being secured.

By the end of the war, the CMY section controlled all UK collection resources in the European theatre, and allocated tasking through a process in which all involved were aware of what needed to be collected, and why, and to what extent. Not every message on every network needed to be collected and decrypted in full every day. For example, a reserve formation might only need to be monitored at its morning call-up once a week to confirm that there was no change in the list of subscribers or their location, freeing up receiver time for other tasks. The relevant importance of the different services, or of diplomatic traffic sent by wireless, could be rebalanced on a daily basis as requirements changed. But this only worked because there was a reconsideration of "need to know": in fact its replacement. By sharing the maximum amount of relevant information CMY was able to optimise the use of allied resources and produce more wanted intelligence for customers. London ministries stated their requirements and people who understood the technicalities of Sigint collection and processing answered them.

The compartmentation which "need to know" had led to within GC&CS was replaced in post-war GCHQ by a system which used vetting as a starting point for creating an organisation with far fewer compartments than had operated at Bletchley Park. Access to Sigint reporting might still be rigorously compartmented outside, but within the organisation there would be no artificial barriers to knowledge sharing.

This doesn't mean, of course, that everybody within GCHQ had access to everything: a member of staff couldn't simply walk into another office and demand to read their reports; furthermore, a process developed which gave extra protection to particularly sensitive lines of traffic; but it meant that a realistic attitude was taken to sharing information.

However, Sigint organisations' need to protect their secrets do not translate simply into the way other parts of the national security community like to handle and process information, and much less how to use it.

A principle created in 1941 when Sigint was first being sent to N Africa applies to this day (though is perhaps more metaphorical than literal today). In it, no recipient of a Sigint report is an action addressee; rather, all are information addressees. You see a shadow of the old signal form every time you receive an email: who it's from, to whom it is addressed, and to whom it is copied. These map onto the From, To, and Info addresses on a signal form. If you are sent a copy of a signal for information, it meant precisely that: you were not authorised to act on that information. The information (the intelligence in the case of Sigint reports) 'belongs' to the originator – the 'From' addressee – and if you are an 'Info' addressee you cannot do anything with the content of the signal without the authority of the originator, the owner.

This concept of ownership is important: 'someone else's secret is never quite so secret as one's own'; but ownership means that the originator can prevent the information being used in a way that might compromise the source of the intelligence or the method used to derive it; it also means that the originator can mandate the standards for storing and sharing the intelligence. This meant that from the 1940s onwards Sigint reports could only normally be read within special facilities (though senior people might have the reports taken to them) by people cleared according to standards agreed to by GCHQ.  

Yet however good the intelligence, it is ultimately valueless if it can't be used. This meant creating a process (Action-On) in which the originator of the intelligence created a plausible alternative source for the information. The classic example of Action-On comes from North Africa during the Second World War: suppose that GHQ learned from a decrypted Enigma message that a convoy carrying supplies for Rommel's Afrika Korps was leaving Sicily for Tunis. Obviously the UK wanted to destroy or disrupt the convoy but simply to attack it would flag up to the Italians and Germans that (at least potentially) the UK had had prior knowledge of the convoy's departure. How could an attack be launched without tipping the enemy off? The best answer was to launch a reconnaissance aircraft on a route which would allow it to spot the resupply convoy and be spotted by it, then allow a sufficient amount of time for the reconnaissance aircraft to radio the information back and for an attack to be mounted by allied forces notionally about other business. This means that some convoys would get though (and some reconnaissance aircraft would get shot up) but these were prices it was thought worth paying.

One of the hardest disciplines to impose was that of only granting access to secret intelligence according to need, and not according to seniority. It was Churchill who, with 'C' removed names from the original list he was given of those with access to Enigma reporting, and at the other end of the production line, restricting access to Y Stations to those with a legitimate reason for entry, rather than simply because it fell under the responsibility of a Command cut across a fundamental piece of military doctrine: how could a Commander be responsible for a unit on his establishment if he had no access to it? The issue was managed, but not simply.

The Second World War saw the first attempt to manage large volumes of secret intelligence produced by large number of people who entered the secret world with little or no background in secrecy. "Need-to-know" was probably the best principle to apply at first: preserving the secret of Enigma was probably one of the most important tasks facing Government in the first half of 1940; but while restricting the circle of knowledge helped protect the secret, it was at a cost of efficient and effective intelligence production for most of the Second World War.

Source Protection

 

Sigint End Product (EP) is the intelligence sent to customers which contains the producing agency's considered view of what material it has intercepted actually means, and is therefore carefully protected, as it can reveal both the source of the intelligence and the methods by which it has been produced. As early as the First World War, was separated into two types depending on whether it had been derived from cryptanalysis or traffic analysis (TA, though up to 1940 it was more commonly referred to as Wireless Telegraphy Intelligence (WTI)). TA reporting was given a wider circulation than cryptanalytic, as it was reasonable to assume that people in other countries knew that their wireless traffic could be intercepted and that it might be possible to draw inferences from it, but both types of reporting were classified. Protecting the source of the intelligence, to ensure that it was not compromised as a source, was part of the process.

There was a rough and ready demarcation between the Services and GC&CS pre-Second World War. The Services believed that they 'owned' TA and GC&CS was prepared to see the Army and RAF distribute TA-derived EP to a wider circulation than was given to decrypts. GC&CS controlled its own product but applied the 'Most Secret' classification indiscriminately to all of its EP, meaning that decrypted diplomatic EP and a decrypted tactical aircraft signal were each given the same classification

With the solution in January 1940 of the current Enigma settings of the German Air Force and later Army the situation changed: 'C' agreed with the service Directors of Intelligence not only to restrict the circulation of Enigma-derived intelligence, but to sanitise EP so that it looked like intelligence from agents rather than Sigint. This meant that 'Most Secret' now covered two different levels of protection: the old 'Most Secret' and the new 'Most Secret CX/JQ' (most intelligence recipients knew that CX meant that the report came from an agent; JQ was used as these were the next two letters to IR (Intelligence Report)).

During the Battle of Norway Sigint was of such operational value that its dissemination became a problem but the battle was over before any handling mechanism could be set up to handle it. The Battle of France came next but it was not until May 22nd, not long before the end, that the German Air Force Enigma was solved regularly. Neither the UK nor France knew how to handle a flood of highly classified material, and neither knew how to interpret it or assess its validity (neither had any idea about how to manage the bilateral exchange either). Some EP reached the British GHQ but is unlikely to have been of any use (see my Sigint Historian: Locking a Stable Door below). The War Office's teleprinter links were of poor quality and completely insecure in France, so an SIS radio link was established in the last few days.

The Admiralty was somewhat better placed. They were already disseminating information to their ships at sea and by using encryption systems with a restricted distribution believed that they could send Most Secret and CX/JQ to their commanders securely (but see Sigint Historian: Ten avoidable problems which made the Royal Navy's encryption exploitable in 1939). Lower-grade decrypts were marked Most Secret by the Admiralty so there was no essential difference in the dissemination of this and CX/JQ.

This was over-complicated. It meant that the value of the intelligence was not at first recognised by recipients and subsequently gave rise to the theory that source CX/JQ was more reliable than (other) Sigint.

Before sending CX/JQ to the Middle East the Y Board agreed two significant principles for overseas dissemination: only to use the most secure cipher systems; and to give Sigint a minimum distribution, and to prohibit redissemination to subordinate commands, except in orders to formations which needed the intelligence for operational reasons, in which case the intelligence would be further sanitised. This clearly established the principle that control of Sigint lay in the UK.

Mobile SIS radio units (SCUs) were used as channels of communication within the Middle East theatre: they weren't intrinsically more secure, but were a time-saving convenience, and a means by which security policy mandated by the UK could be maintained. Any GC&CS EP could be disseminated direct to Commands from Bletchley Park rather than through the Service Ministries. Security of the handling of both decrypted and paraphrased texts was controlled absolutely at either end by 'C'. ('C' wrote to the Director of Military Intelligence in December 1940: "on the question of Security I am directly responsible to the Minister of Defence (i.e. the PM) regarding certain aspects of Y work"; by 1944 he claimed that he was responsible for its Security, not just 'certain aspects' of it: nobody demurred. Did he ask the PM? Did he simply assert his authority?)

When naval machine ciphers were added to the CX/JQ product the Admiralty no longer continue to disseminate Sigint to its naval recipients in the Mediterranean, where this new material was handled in the same way as material for the Army or RAF. But the rest of the output of GC&CS and of service Sigint, both lower-grade decrypts and TA, continued to be disseminated the channels instituted before the war and their security was governed by the Service regulations laid down for Secret and Most Secret documents.

The first attempt formally to classify Sigint and standardise dissemination protocols began in 1941 when it was felt that a 'looseness' had grown up in the way various forms of Signal Intelligence were described and that this looseness was in itself a source of misunderstanding and consequently a danger to security. 'Y Intelligence' was defined as a category of 'Intelligence obtained from a scrutiny of foreign messages intercepted, particularly as to callsigns, frequencies, volume of traffic, indications of priority and from DF bearings'.

A generic codeword ULTRA now covered high grade traffic: in other words, the marking MOST SECRET ULTRA would appear on documents. Its use meant that Sigint no longer needed to be sanitised to suggest that the originator was an agent. As high grade diplomatic became important to Service commands ULTRA began to cover a lot more than Enigma, and needed to be handled and disseminated to many more locations. To avoid duplication and a consequent risk to cipher security all ULTRA now had to be passed through GC&CS. This also meant that security regulations governing both the use and the handling of the ULTRA intelligence should be promulgated from the UK to all recipients. It was difficult to get an agreed set of regulations which would meet the security requirements and the practical requirements of overseas centres, while giving sufficient latitude to the Commands to use the intelligence: this took until June 1942.

In the summer of 1943 Edward Travis negotiated an agreement with the War Department in Washington which included the principles of the existing ULTRA Regulations and Sigint Security, meaning that US would in principle conform to UK regulations. The first step was the issue in October 1943 of an agreed 'Nomenclature', a set of definitions, most important of which was that the words 'Signal Intelligence' included the whole Sigint  process: interception, decryption, analysis (cryptanalysis and TA) and reporting; and 'Y' was limited to interception at stations and DF. More Sigint codewords were set up so that ULTRA was used for the EP from high grade codes and ciphers; PEARL, for EP from low and medium grade codes and ciphers; and THUMB for EP from TA.

The drafting of the complete instructions took much longer, not because they were controversial, but because it was hoped to produce a set of regulations applicable worldwide (in Europe the US had simply adopted UK procedures). They were produced in three separate documents, finally issued on 1 February 1944, but the Admiralty refused to bind itself, adding a statement saying effectively that it would do its own thing, though that just happened to be the same thing as promulgated by the regulations.

The next necessary step was to ensure that analogous regulations covering both British, Australian and American Forces were promulgated in the Far East and SWPA. UK regulations applied in India, but not in Australia, and the Americans, while they had subscribed in Washington and in Europe to the British regulations, had specifically not done so for the Pacific theatre. In July 1944 agreed regulations for ULTRA were promulgated, and in November 1944 for PEARL and THUMB. The USN, however, did not accept them and issued their own regulations in April 1945, dividing Special Intelligence into two categories only – ULTRA, which they extended to cover what in Europe would be considered PEARL, and PINUP, which was essentially THUMB.

It took the formation of STANCIB as an overarching authority in the US, equivalent to the Sigint Board in the US, and, in the UK, the Admiralty's grudging acceptance that GCHQ was the 'owner' of Sigint to allow negotiations for a single set of regulations to take place after the signing of the BRUSA Agreement in 1946, regulations which were to be applied in the US and US, and eventually in Canada, Australia and New Zealand.

So much for handling and dissemination: like Protective and Personnel Security, both of which I have written about before, they are aspects of security around which it was possible to write regulations (however difficult it might be to get sailors to sign up to them) and to enforce. There are still two more aspects of security to deal with, however, and these were much more subjective: 'Need to Know' and 'Action On' are integral parts of Source Protection. 'Action On' is a core issue: there is no point collecting information and turning it into intelligence if nobody can use it; but equally, there is no point using intelligence if its use will make the enemy realise that its secret information is known. 'Need to Know' makes obvious sense: nobody thinks that all secret information should be widely available to everybody; but who decides who needs to know what?