Oh là là! A French Farce in the Records of British Intelligence

 

An entry in Guy Liddell's diary for 1 January 1941 (KV 4/187) might lead one to the conclusion that old fashioned farces were not quite as far fetched as I used to think when watching Brian Rix.

Admiral Emile Muselier was in London, attached to General de Gaulle's Headquarters as Commander of Free French Naval Forces. Forged letters suggested he was in secret dealing with the Vichy regime and on New Year's Eve 1940, The Prime Minister, Winston Churchill, ordered his arrest. What happened, or at least the way Liddell told the story of what happened, probably confirmed in a generation of intelligence officers some of the prejudices they had inherited about the French.

"We have now obtained 3 more letters from Collin who says that he has obtained them from the same source. They deal with a variety of matters and all incriminate Muselier. His Chief of Staff, a Lt Villiers, also seems to be involved. We can find nothing wrong with the text of the documents Kenneth is giving them to Desmond Morton under the same safeguards.

At about 10 pm I was rung up at Tring by Harker. He said that the PM had given orders for the arrest of Muselier, Villers and Mlle d’Anjou. I offered to come up but he said he did not think this was necessary. He and Kenneth went to see Morton, when Kenneth once more emphasised our doubts about the source of the information. Morton said that the PM had given his order and there was nothing to be done but to carry it out. Col Angenot was fetched and attempts were made to get hold of Gen de Gaulle. He was away on leave and it was found impossible to get into touch with him. Angenot rather regretfully agreed to the action suggested. Although he thought the documents bore the stamp of genuineness he would have liked Gen de Gaulle to have seen them before the arrests were made.

The Home Secretary was visited by Harker and Morton and gave the necessary orders to the police. Luckily we had already warned Canning during the afternoon that some action might be taken. In deference to Angenot’s wishes no action was taken against Moret, Muselier’s Chief of Staff, but at his request Mlle Herincx was put on the list as it was thought that if there was any conspiracy by Muselier she would be the most likely person to have documents. The police took action during the course of the night. Mlle D’Anjou was found in bed with Lisboa and Mlle Herincx with a Dr de Kerguelen. This is the first occasion on which they had slept together and it was his birthday. The police saw fit to bring in the doctor on the grounds of his association with Mlle Herincx. Lisboa, hearing the police entering Mlle d’Anjou’s flat, thought that they had some complaint about the blackout and hid in the lavatory. He eventually emerged and claimed diplomatic privileges. While he could not object to the flat being searched he refused to allow the police to touch any of his own clothes.

Villers could not be arrested till 8 am as he was on night duty at the Free French headquarters, and it was found that the Admiral was down at Windsor spending the night with a lady friend. He eventually rolled up at about 9 am. By way of precaution the police pulled in his valet and chauffeur. The Admiral protested mildly and said he hoped the matter would soon be cleared up as it would create a very bad impression in the Free French Navy."

Security at Bletchley Park

One way in which British Sigint during the Second World War anticipated the way many people work today was in having not just to find ways to provide physical security for the vast quantities of sensitive data being created, but in persuading large numbers of workers with no instinctive or habitual feeling for secrecy to protect the material they dealt with. I've written about the way in which infiltration by communists or communist sympathisers was handled – but how did Bletchley Park ensure that its site remained secure and persuade the ordinary people who made up its staff not to talk about their work, to the extent that few said anything about their involvement with Sigint for thirty years after the war came to an end? 

The initial approach to security at Bletchley Park was to surrounded it with secrecy. The name "Bletchley Park" was not to be mentioned: instead it was referred to as "Station X"; staff were forbidden to reveal the location, even to their families. However staff had to billeted and it was impossible to prevent it being known that Bletchley Park had been taken over by the Government. SIS came up with a cover story – that Bletchley Park was involved with the Air Defence of London – which it was thought would satisfy local inquisitiveness, but this cover story was not used when Bletchley Park was temporarily occupied in 1938 during the Munich Crisis and staff were told what their cover was until after the site was occupied in August 1939. The initial staff scattered about the neighbourhood – members of the Foreign Office, professors of Modern Languages, historians and mathematicians – had no obvious qualification for air defence: it is hard to believe that any one of them could have answered the simplest question if asked.

After SIS had mostly returned to London, the GC&CS leadership decided to change the cover story and to refer to the organisation at Bletchley as "Government Communications Headquarters", a name that was vaguer and potentially covered a broader field than Air Defence. But again the first staff of GC&CS knew about the new name was when in October 1939 they found it displayed on a large white painted signboard at the entrance gates – a sign which was subsequently removed.

The idea of keeping secret where staff were broke down almost at once. People had lives to live outside work and consequently had to have an address and, anyway, after a time some moved their families into houses nearby. At first an accommodation address had been provided: Room 47, Foreign Office; but as numbers grew the amount of work for the Foreign Office became too much, the last straw, allegedly, was when a motor cycle was delivered there. It was only in 1942 when a Bletchley PO Box Number was arranged, mainly for those whose billet address was uncertain, and a London Box Number was arranged which could be used for letters sent abroad (on which the Bletchley address was forbidden).

(There were fewer problems with the Y Stations: there was no question of concealing their presence or their function. But it was common knowledge that WT was used by the Services and the normal measures common to any Service station to prevent unauthorised visitors were satisfactory, though care was needed to prevent senior officers from entering without authorisation. Most commanding officers adopted some cover story for local use, for example that they were relaying weather reports.)

At Bletchley, physical security developed slowly. A solid iron ring fence was put up in the spring of 1940, but as GC&CS grew the fence had to be considerably lengthened and chain wire netting was substituted for the ironwork. There were only two official entrances. The most that can be said for the fencing was that it offered a sort of deterrent: it offered virtually no obstacle to a determined person and was neither lit nor patrolled at night. (During a Home Guard exercise early in 1943 the attackers removed a complete section under cover of darkness with no more formidable weapon than a spanner, and so attacked the defenders, somewhat unsportingly it was felt by the defenders, from the rear.) But it kept out casual intruders and ridiculously insecure as it probably was, it served its purpose during the war.

Every member of GC&CS and certain regular visitors were issued with standard passes. Theoretically passes were examined at the entrance gates but in practice they were simply waved at the gate guards by staff on their way in. There were two kinds of guard on the gates, Military Police, with armed sentries, and unarmed Foreign Office Security Police, recruited from pensioners in the Metropolitan Police. They got to recognise GC&CS staff and were probably the best security GC&CS had against infiltration. The Military Police boarded the incoming coaches and stopped all cars so that passes could be shown. Staff without passes were detained until recognised or claimed by their sections and these cases were reported to the Administration. Of course there were plenty of cases of people who had forgotten passes coming in at busy times and dodging the guard, of passes being handed through the fence out of sight of the gate by someone who had already entered, and of passes lent by someone coming off duty on foot to a pass-less colleague still outside the gate. In fact the number of forgotten passes each morning was considerable and steps had to be taken to make getting those staff into work as tiresome as possible, both to the individual and to their section, which had to send somebody to the guard hut to vouch for their identity. The alternative would have been to refuse entry altogether, which as there was no public transport would have left most individuals who were billeted outside Bletchley with no means of getting back to their billet as well as the loss of a day's work. There were relatively few cases of passes being lost: a fine was imposed to pay for a replacement. Like the fence, the pass system was adequate for the time and place, though not really offering much in the way security.

Temporary passes were issued to craftsmen and others who had business within the perimeter by BP administration. They either remained in sight or were escorted by the Military Police. Visiting military officers also received temporary passes and had to be vouched for by one of a small number of authorised staff from GC&CS. They were also escorted while on site. Further limitations were put upon the entry to work areas both by visitors and by staff from other sections, according to their "need to know".

Standing Orders provided that no room was to be left unoccupied unless all papers had been locked away. At times, whole rooms had to be locked and regarded as "cupboard rooms". The Foreign Office police patrolled buildings each night and all open windows or unsecured papers were reported, papers being kept by the police until the next morning. A "security officer" was appointed in each section to coordinate this within the section but there were many examples of carelessness among staff unaccustomed to this sort of behaviour. It was made more difficult anyway because the cupboards supplied were of poor quality and many of their doors opened enough when locked for a hand to be inserted without difficulty and the fastenings could be broken away by a sharp pull. It made all the fuss made about securing classified material seem futile.

Paper was by far the greatest security issue for GC&CS. The quantity was enormous. Forty or fifty thousand enemy signals entered GC&CS every day and the Cypher Office was handling between two and three million cypher groups (a further twenty or thirty thousand messages between BP and UK authorities) a week. The floors of the signals and deciphering rooms were covered in tape all of which had a gummed underside which stuck to shoes on a damp day. Each section generated formal papers of every kind and received large quantities as well. Most was carefully handled and the registration process prevented even more problems. But there was a lot of unrecorded paperwork as well, and the acute national shortage of paper meant that paper had to be kept for recycling rather than be simply destroyed by burning.

The routine for dealing with confidential waste was to have it collected once a day, sacked, tied up, locked up and taken once a week to a local paper-mill where it was tipped into bleaching vets under the supervision of the GC&CS security officer who had taken it there. This process worked reasonably well. The only difficulties came from GC&CS staff. They produced three kinds of waste – white paper, coloured paper (e.g. carbon paper, brown paper, cardboard boxes) and "hard core" which included almost every conceivable object except paper. The paper mills insisted that white paper should be separated from coloured paper as only white paper waste could produce pulp clean enough for new paper (coloured pulp was used for cardboard). Any hard object in the waste was liable to break the machinery, and glass in particular was dangerous to the workers. Three containers had to be supplied to every room for the three different kinds of waste. Paper waste of both grades was treated as secret while hard core was dealt with at the local council tip. The problem was to persuading staff to use the proper container and from a security point of view the danger lay in the hard core bins. Each member of staff was told how things worked on arrival in their section, was given written instructions, was again specifically reminded at a Security lecture, but carelessness remained an outstanding feature.

Physical security measures at GC&CS were probably not any worse than procedures in the Ministries, except that the grounds in which the offices stood were more vulnerable than a London building. The title "Government Communications Headquarters" worked well enough, though this disguise wore rather thin when the Army ordered shoulder flashes to be added to uniforms and the Bletchley area was thronged by soldiers labelled "Royal Corps of Signals" and "Intelligence Corps" – from a GC&CS point of view an unfortunate association of ideas. But in general GC&CS consistently pursued this policy of being low key, avoiding appearance before local tribunals or in any matter that might engage the attention of the Press or public. The cover stories probably increased rather than reduced curiosity. By far the best protection for GC&CS staff was simply to say that they couldn't talk about their work: to appear, as Churchill remarked of them during his visit 'innocent though engaged in a sinister occupation'.

Every new entrant (civilian or service, at Bletchley or at stations) read and signed an extract from the Official Secrets Act as did everybody leaving in a formal "signing off" process. In GC&CS after the signing of the Official Secrets Act staff were warned that no mention of the nature of the work outside the organisation was allowed, and this warning was included in the Standing Orders issued to them. Further security instruction was left to Section Heads to handle and this system continued until the beginning of 1942 when all security-related matters were centralised when Henry Hayward became Senior Security Officer for GC&CS.

Being "war entry" himself, he realised that suddenly exposing new entrants to highly secret information was an unusual experience and potentially a source of acute anxiety to some, while for others security rules would be no more important than rationing rules or petrol restrictions, which most people were prepared to dodge on the quiet. His solution was to ensure that Security became part of everybody's work rather than a bolt-on, and to do so, he rethought the way that new entrants were trained in security.

His plan was to give a simple lecture to every new entrant a few days after they arrived, followed by the signing of a solemn declaration which listed the main points of the lecture. This paper dealt in the main with the best answers to be given to ordinary everyday questions from acquaintances. It was handed out to be read and signed after the lecture, returned to the Directorate and, as it was a confidential document, its arrival or non-arrival until chased offered a clue to the reliability of the individual. This did not take the place of signing the Official Secrets Act, but supplemented it. Each batch of recruits – the intake was at first about 30 arriving every Monday morning – attended the lecture some three or four days after being signed on. They were divided into three categories according to the "need to know" their work attracted: those engaged in Sigint proper; those employed in support areas such as the Communications Section where there was no need for them to hear about the methodology of Sigint; and staff such as messengers, maintenance and catering, who might enter offices at times and who would certainly overhear other people talking about classified subjects. The lecture was varied according to the audience, the last category being especially warned against inquisitiveness, talking outside the perimeter of anything they saw (for example machinery) or anything they heard, but were otherwise given no information about the purpose of the organisation. The same lecture was given to the WRNS at Stanmore and Eastcote. Hayward visited these stations at longer intervals and audiences varied from about 100 up to 250.

His lecture always covered the following points:

1) Explanation of the provisions of the Official Secrets Act.

2) The Purpose of GC&CS.

3) The effect of its work on operations.

4) How it might be lost and the effect of doing so.

5) 'There is only one way of keeping a secret, and that is to tell it to nobody' not even to the nearest and dearest or others in the same uniform.

6) Behaviour: 'Do not surround yourself with mystery and avoid arousing curiosity' and how to answer casual or not so casual questions.

7) Not to write indiscreet letters.

8) The principle of need to know. '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', and how this led to the principle that members of one section should not discuss their work with members of another except when necessary.

9) The honour of the Service.

(Before anyone asks, I do not know what "The honour of the Service" covered.)

Hayward gained a further insight into the sort of issues staff needed to be warned about as all security breaches were reported to him. Most cases fell into one of three main categories: victims of the confidence trick – senior officers saying 'I know all about your work as I was an intelligence officer in the last war' or parents saying 'You can surely trust me'; people who deliberately attracted attention ("men of mystery"); and what he described as "chatterboxes and letter writers". Of these the last category was by far the largest and the most easily dealt with.

Staff were told that it was their duty, however unpleasant, to report security breaches at once and Hayward ensured that incidents were handles in such a way as to minimize any personal animosities. In his words: "It was made to appear rather more a question of helping a weaker vessel than reprimanding a naughty child."

Hayward arranged periodically for a week or so's censorship on all letters leaving or entering the area in which GC&CS staff were living. This produced on each occasion a small crop of letters which were returned to GC&CS for action. No really serious security breach was discovered and all were easily dealt with, but it demonstrated the need to explain in simple language what constituted careless talk and what was meant by security.

American Air Force officers regularly invited WRNS and other young women employees to their dances. Unfortunately the drinks served tended to be both stronger and more plentiful than most of their guests were accustomed to. The presence of women in Naval uniform in the heart of the country was intriguing and led to a degree of innocent questioning. So many cases of indiscreet talk occurred that GC&CS felt obliged to ask the WRNS not to allow their personnel to visit certain American stations. The problem was passed on to the US Army Sigint authorities in the UK, who sorted things out at their end. The security problem was perceived to be greater because of the likelihood that some at least of these officers might fall into enemy hands.

There were some cases of mental breakdown. Fortunately in an early case the patient, by that time in a nursing home, wrote to a colleague about work matters. It was immediately appreciated that a letter like this could be sent to anyone. MI5 was called in and arranged for doctors and nurses to be interviewed and letters censored. This became a standard procedure.

Security breaches during the Second World War were relatively infrequent and easily dealt with.  The idea that maintaining secrecy was an integral part of everybody's job became embedded within the organisation, and many of the practices begun there continued after the war, and indeed to the present day.

Sigint Liaison with Finland

 

The UK now has a Defence Agreement with Finland and Sweden, and will soon be formally allied to both countries in NATO. It is not well known that for a short period in the Second World War the UK and Finland found themselves on the same side: our enemy's enemy was our friend and in spite of the alliance between Nazi Germany and the USSR, German occupation of Poland, Denmark and Norway, the Soviet occupation of the Baltic States and the part of Poland the Germans had agreed to let them have, and Swedish neutrality, the UK and Finland enjoyed a Sigint partnership for just over a year.

British Sigint had had relationships with the French, Italians and Americans during the First World War. These had all disappeared by the time GC&CS was formed on 1 November 1919. RAF Sigint did its own deal with the Estonian military Sigint authorities, and for most of the 1930s equipped and trained the Estonians in return for Estonian intercept logs of traffic of the Soviet Air Force, though this ended in 1939. In the 1930s, under the auspices of SIS a relationship was developed with the French to discuss Enigma, and from this grew the 'Enigma Relay', the exchange of information that led to Enigma becoming an exploitable cipher system.

This meant that GC&CS had become receptive to the idea that foreign Sigint services could be met as partners and early in 1940, this led to the idea that somebody should visit Finland to see whether the Finns were doing anything against the Soviet Union, the ally of Nazi Germany, that might benefit UK Sigint. At this point there was no dedicated UK effort against the Soviet military: an interservice cryptanalytical section would not be set up (in Wavendon, near Bletchley) until the summer of 1940.

Tiltman, the Head of the Military Section, went to Finland to meet the Finnish Sigint organisation, a meeting brokered by the SIS representative in Helsinki and the UK Military Attache. He arrived in Finland on March 1st 1940 and stayed for ten days most of which he spent with Major Hallamaa, the head of Finnish Army Sigint, at Kerava. Hallamaa showed Tiltman the whole of his organisation and expressed the willingness of the Finnish General Staff to cooperate fully in Sigint matters with the British.

The Finns were willing to exchange their knowledge of Russian codes and ciphers in return for the radios they were very short of. They needed 50 receivers, 6 DF sets and 6 high-powered transmitters to link their units in the field. The War Office in London confirmed that some of the equipment was available and the Finns handed over a forty page handbook on Russian Army and Naval communications.

The equipment was released on 15 April 1940, and the Finns were further informed that the UK would fund the Finnish purchase of further radio equipment in Sweden up to the value of £500. Some equipment arrived in Helsinki but when another GC&CS officer arrived in Finland to develop liaison on the Russian target he found that the Finns had only obtained 4 receivers, though a search while he was there produced three of the DF sets as well, and the Finns appeared satisfied that the British were acting in good faith. They agreed to provide Soviet intercept provided the British reciprocated: in the Finnish system the clerical effort involved would have to be justified to higher authority by a quid pro quo. They gave the UK the current encryption system being used by the Soviet Baltic Fleet as well as military systems which had become mainly readable. In return GC&CS offered its work on encryption systems used by the Soviet Navy Black Sea Fleet which was being taken in Palestine.

The exchange of intercepts was not straightforward. The air route between the UK and Finland was only open during the summer months, and the Finns were unwilling to open a new two-way radio link to the UK so the only way was to send the traffic by air to Stockholm from Helsinki in a diplomatic bag and to forward the traffic from there on commercial wireless circuits and vice versa. This would have worked if a Typex machine could have been sent to Stockholm and if sufficient Typex capacity had been installed at Sarafand to deal with the Black Sea traffic. However, there were significant problems in the supply of Typex, and by March 1941 Denniston argued that if only GC&CS could be allocated 10 lbs weight in the Stockholm daily bag the need for Typex would disappear, but neither Typex nor the 10 lbs of freight became available.

In spite of all the assurances it had given, the War Office did not actually send the rest of the radio equipment originally promised. It took until summer 1941 before this was sorted out and by then the situation had changed completely. The Germans declared war on Russia and a German mission was sent to Finland just as the final decision to send the missing sets was taken.

The last signal from Finland contained an assurance that they would not reveal to the Germans their Sigint cooperation with the UK and asked for an assurance that the British would not tell the Russians of Finnish cryptanalytical success against Russian systems. This assurance was given, and the Finns and the British each kept their promise (something perhaps easier for the British side than for the Finnish).

GC&CS developed its links with the US, and maintained its links with France and the exiled Poles until December 1942, but this marked the high water of non-Five Eyes cooperation. The Finnish experience had shown GCHQ that a buccaneering attitude to foreign relationships might bring results, but always at a potential cost of the partnership being prey to other considerations, and the dispersal of French and Polish cryptologists after the Nazi occupation of Vichy led to a new and cautious approach which would last for many years.

Sigint Liaison with the Russians

After the German invasion of Russia in June 1941 a military mission (No 30 UK Military Mission) was sent to Moscow and learned that the Russians had a Y Service. In August, 1941 a Y officer from the Middle East went to Moscow. He was given little information, and wasn't allowed to see anything of the Soviet organisation. However, as British relations with the USSR had been bad for many years this was considered unsurprising, and in October 1941 the War Office on its own initiative attached an Army officer (who had been working as a Sigint traffic analyst) in 30 Mission. At the same time the Admiralty negotiated permission to build a Naval Y Station in the far north aimed at providing early warning of any attack on the convoys planned to bring supplies to the Russians. On the Army and Air Force side it was hoped principally to obtain Russian-intercepted German traffic and some help if possible on Japanese systems. In fact, apart from the supposition that Russian Sigint would be less efficient than British there wasn't any clear policy, other than that allied intelligence liaison was a "good thing". 

The Admiralty received Soviet permission to erect a Y Station at Polyarnii, near Murmansk, and British permission to give the Soviets information about Auka (a low-grade Luftwaffe system), and, in May 1942, sent a naval officer from GC&CS to Murmansk to arrange for the exchange of Naval and TA intelligence. As a result of this some naval intercepted traffic reached GC&CS and there was also an interchange of DF bearings.

The War Office representative also made some progress. He was authorised in February 1942 to train the Russians to break the German police ciphers which were being used in rear areas on the Russian front, as well as showing them some traffic intercepted in the UK. (It was never the intention that British success against Enigma should be revealed.) He reported that this had produced a favourable reaction and he asked to be allowed to expand the exchange, giving the Russians identities recovered from callsign analysis of certain German stations in return for traffic intercepted in Russia. In June 1942 he was recalled for discussion of policy and went back to Moscow as representative, not of the War Office, but of the Y Board. But the mood in Moscow had changed: the Russians stalled and eventually in November the Head of the Soviet Army section dealing with Traffic Analysis suggested that cooperation should be discontinued.

Naval cooperation in the far north continued on a restricted basis, though some intercepted material inaudible elsewhere did reach the UK. This lasted until spring 1943 when, just as the UK staff were preparing to hand over another batch of Y material, the Russians suddenly entered the British site, sealed up the transmitters and took away the "meaconing" apparatus (a means of falsifying German Beacon transmissions.) At the same time it came to British knowledge that the German Y Service was reading some high echelon Russian cipher systems without much difficulty. Convoys were not actually in operation at this time, but were expected to resume and the closure of the station and Soviet insecurity greatly increased the hazards of running them.

In return for German Police material, the UK had given the Soviet military the Japanese Military Attaché code, the "Bird book" and index (the GC&CS process for breaking out German enciphered callsigns), the solution to German aerodrome serviceability reports, the process for recovering German police keys, Auka, and some ISOS keys. The Russians had also been made aware that the UK could read the Army tank code, Army medium grade field ciphers as well as the cipher used by one of the German sabotage units. The UK side decided that unless and until the Russians resumed cooperation, no further material should be sent. There was no point in keeping a representative in Moscow and the liaison officer, while retaining the title 'Russian Liaison Officer', was relocated to GC&CS. GC&CS had only one vote on the Y Board but it was a significant one. its attitude towards Russian cooperation was becoming more assertive and more reluctant. 'Jumbo' Travis wrote to Heads of Sections in May 1943 saying that he was prepared to consider an exchange, but only if there was a solid return "as I am not now a believer in Russian cooperation".

Although it had been decided that the Y Board should have no representative in Moscow, 'C' felt that an SIS liaison officer might usefully represent Sigint as well. One went to Moscow in the summer of 1943, just in time for several things to happen all at once. The Soviets asked for a full description of the German Enigma machine; they captured a copy of Auka themselves; and German Y Service traffic intercepted by the UK revealed that Russian ciphers were still being read by the Germans.

A meeting took place in summer 1943 after the British Ambassador made representations to Molotov, and it became clear that the Soviets' main interest was to find out what exactly what the British evidence of Russian cipher insecurity was. They were told that the information had come from a disaffected Austrian prisoner of war and from information from Japanese Military Attaché decrypts; they were also told that the UK side would give no further Sigint-derived information until the Russians delivered on their promises of the previous year. There were a few sporadic meetings and it became perfectly clear in spite of the SIS representative's attempts to put the best possible interpretation on what was going on, that the Russians were trying to get what they could from the British without giving anything away themselves. Telegrams continued to pass desultorily throughout 1944 and an Enigma machine and a small amount of very low level Y information was sent, though probably more for SIS's benefit than for Sigint's. Before the end of the war cooperation had ceased.

Why were the Soviets so reluctant to carry out an exchange of material? GCHQ believed post-war that the Soviet Sigint organisation had made the authorities in Moscow aware that the material being offered by the UK was low grade and that therefore either the UK was keeping its aces up its sleeve, or it didn’t have any capability worth wasting Soviet time on.

In my last post I told the story of how some information derived from Enigma decrypts had been published after having been passed by military censors. Commenting on Twitter @jock_bruce said that "in that story the point is that the folk clearing stuff for publication need to know what they’re actually protecting". I think that there is a similar issue here: those making decisions – the single services, and subsequently the Y Board – didn't understand that any half-way competent Sigint organisation would realise that valuable information was being withheld.

Sigint liaison worked with the French and the Poles when there was a full exchange of knowledge between the national Sigint organisations of each country, and subsequently worked with the US and Australia, Canada and New Zealand, because there was full sharing and integration of staff in each other's organisations. It couldn't work if the exchange was partial and low-level, and it certainly wouldn't work if non-Sigint personnel were representing Sigint.

 

Locking a Stable Door

There is an interesting story in Guy Liddell's diaries (The National Archives (TNA) KV 4/187 and 4/189) about publication of Sigint secrets in a book published in 1941.

March 8th (1941)

SIS are in a great state about the publication of a book called The Diary of a Staff Officer, who (sic) in addition to criticising the French and British Commands in rather an outspoken manner makes reference to work affecting the GC&CS. I communicated first with Mr Ray of Methuens, the publishers, and then with Dick's brother who is a partner in the firm. 1,900 copies have already been issued and since further demands are being made by the booksellers, most of them must be in the hands of private individuals. Meanwhile, another 7,000 copies are in preparation and are to go out on Tuesday next. Dick's brother tells me that the book was submitted to the MOI and passed by all 3 service representatives before Xmas. It was then published serially in the USA. It is possible however that the offending passages may have been omitted. A few copies have gone to Canada and the book has been extensively reviewed here in the Press. I am suggesting that the 7,000 copies should not be circulated and that the censorship and D.4 should be warned against letting any of them out of the country. I feel that if we do more than this we shall only be drawing attention to what we are anxious to donceal (sic). We shall be in a better position to decide on Monday.

March 10th (1941)

I saw Stewart and Hopkinson about the officer's diary. We discussed the problem in all its aspects and thought that before coming to a definite conclusion it would be wise to see Gribble at the earliest possible moment.

March 11th (1941)

Stewart, Lennox and I saw Gribble at the WO. He admitted that he knew the messages came from a very secret source but he thought he was amply covered by having submitted his diary for censorship. He admitted however that he had shown the document previously to his agent to see whether its contents were like (sic) to interest the public if they were published in book form. It was explained to him that certain passages constituted a grave indiscretion and that it was in the public interest that he should cooperate with us in doing anything possible to pick up the pieces. We eventually agreed that even though the offending passages had appeared in the Saturday Evening Post it would be better to issue the new edition in amended form. Gribble was to tell his agent that he wished to make certain amendments in the text and therefore that he would like the return of the proof copy from America before any further action is taken. As regards the Manchester Evening News who were asking permission to publish the book in serial form, it was decided to see first whether they were proposing by their own selection to exclude the offending passages. If not, we should have to say that the book could not be published serially until certain amendments had been made which the author considered desirable in the light of subsequent information received.

…

In the afternoon Dick's brother came down and we discussed details about Gribble's book. It was apparent that if the offending passages were taken out it would be quite clear that a new one had been gummed in. We therefore decided to buy up the whole of the second edition which was already bound and have arranged that the offending page in the other two editions should be removed altogether, with those which were joined to it. These would be collected before the new amended pages were delivered to the printer.

2^nd February (1942)

According to an intercepted letter a New York publisher is trying to arrange with Watt, London, for the publication of Major Gribble's book Diary of a Staff Officer in German. It is to be printed in Switzerland. Lennox has got hold of Gribble and will tell him to stop the publication. If the book circulates in Germany there is a possibility that what has been overlooked may come to light.

(Key to people: Dick is Dick White, MI5 officer and future DG; Stewart is Stewart Menzies, 'C'; Hopkinson is probably Henry Hopkinson, PS to PUS FCO (subsequently Lord Colyton); Lennox is Gilbert Lennox, MI5 officer and responsible for MI5 liaison with the War Office.)

Fascinated by this story, I managed to locate and buy a copy of the first (offending) edition of this book. (The second edition was, presumably, bought up and destroyed; and there were at least third and fourth editions according to abebooks.)

The offending passages appear to be two of the entries for 12 June 1940. Here is the entry for the whole of the day.

June 12th. 1130 hours. The German have three fresh army corps South of RHEIMS. This town was occupied yesterday when the French made a complete withdrawal to the MARNE. There are now 80 German divisions on the CHANNEL – MONTMEDY front. The French possess some very exhausted 35 divisions. There is no longer any hope of success for the French.

PS (private sources) is providing a fund of information. There were 45 messages last night.

1200 hours. The last of these messages consisted of a single word: "SEDAN". This is the German word for bombing PARIS.

1210 hours. It was repeated to us again today that the lack of enthusiasm in the French armies could be attributed to the fact that one third of them was drawn from the occupied territory. Even more, it is thought that at least half the soldiers in the French army have now lost their homes through German occupation.

2300 hours. Very unpleasant news tonight. A big break through over the SEINE with enemy reported as far over as DREUX and EVREUX. Looks like the next move towards the SEINE.

It is pretty clear that Major Gribble was trying it on. He knew how sensitive the material originated from Sigint was, and he knew that the volume of reportable intercepted messages was significant. But he guessed that the military censors wouldn't know as much as he did. I imagine that the fact that "SEDAN" was identified as a codeword message (CWM) meaning "Bomb Paris" was what caused the stir when the book was published, but it's hard to believe that the Germans hadn't assumed that the CWM would be compromised as soon as Paris was bombed.

This diary entry was written before the most severe levels of security were designed for the protection of Sigint, and it is in part because of what happened in France that things were tightened up. As de Grey says, in Appendix III of his Organisation and Evolution of British Sigint (TNA HW 43/78):

The policy adopted in regard to the Enigma decrypts had no repercussions during the "Sitzkrieg" [the Phony War] – they were dull and of no immediate operational value. It was not until the Battle of Norway that the intelligence became of such operational value that its dissemination in a wider field became a problem. Norway was over before any organisation could be set on foot. The Battle of France supervened but it was not until May 22nd that the current German Air Force key was solved and thenceforward solved regularly – that is until a week or two before the end of the Battle. The arrangements to supply GQG [Grand Quartier General: the French GHQ] with results were untried and neither Ally was versed in the exchange of such material. GHQ and AHQ had not had the experience of receiving a flood of such material, were in no position to interpret its significance and were in ignorance of its reliability. The whole front was crumbling and although it is possible that some of the information reached the higher commands it is doubtful whether it was of any use. The War Office channels of dissemination were abandoned possibly for fear of their insecurity and SIS WT was substituted in the last few days. The difficulties of secure dissemination to the commands in the field were thus fully brought to light.

The diary entry illustrates de Grey's point: as well as copious and detailed predictive intelligence from intercepts, Gribble's office was handling top level information about German and French Orbat and German movements, as well as engaging in dubious analysis of what might or might not be demotivating the French Army. This isn't a picture of a well-functioning Intelligence Staff: those involved had no training in or experience of what they were supposed to be doing.

The solution chosen to solve the Sigint part of this problem was ULTRA and the special handling procedures associated with it were effective in protecting the fact of successful cryptanalysis and the products which that success brought, but at a cost: not everybody who handled intelligence had access to all relevant intelligence on a given subject. The level of clearance needed to have access to the most sensitive intelligence was granted to only a small proportion of members of intelligence staffs. That in turn produced problems of its own.

 

 

 

 

 

 

 

The Yangtze Incident And A Do-It-Yourself One Time Pad

The story of HMS Amethyst and the Yangtze Incident used to be well known, but is less so today. Briefly, during the Chinese Civil War HMS Amethyst was sailing up the Yangtze from Shanghai to Nanking to provide support to the British Embassy to the Chinese Nationalist government which was temporarily based there. The British frigate was fired on by Chinese communist forces and severely damaged, and was forced to anchor for ten weeks, every attempt to move provoking renewed fire from the communist batteries. On the night of 30 July 1949 Amethyst made a daring and successful 100 mile dash down the Yangtze and rejoined the fleet. there is a little known cryptographic footnote to this story. 

After being attacked, HMS Amethyst had prepared to scuttle herself and had destroyed all crypto materials. From comments made by the local communist commander during protracted negotiations, it was clear that his forces were intercepting the plain language traffic between Amethyst and CinC Far Eastern Station, so how could Amethyst and the CinC plan her escape?

The Chief Naval Signal Officer Far East (Cdr C R Williams RN) came up with a plan to create a One Time Pad (OTP) which would then be used to re-encipher message sent using the Government Telegraph Code, a copy of which was held by Amethyst but which was also known to be in the possession of the communists.

The OTP was created as follows: in a first column, the surnames of all RN officers and men on board were listed in alphabetical order.

Column two listed the first name of the next of kin of each of the people in column one.

Column three listed the placename in the address of the people in column two as given by the person in column one.

Column one was now discarded.

Working down column two, letters were converted into four figure groups – so JOAN became 1015 0114. Groups were written across the page, with five four figure groups on each line. Once column two was complete, the same process was used with column three.

This pad was only used for one message. In it, Amethyst was told the times, frequencies and indicator groups of a series of dummy messages which would be addressed to CinC FES on the Fleet broadcast. Amethyst should copy these messages and use the groups transmitted to make 'In' and 'Out' pads. She was also told how to use the pads without a codebook.

During the afternoon of 30 July Amethyst sent a Flash signal: "DTG 300657Z July. Top Secret. CinC info Concord from Amethyst. I am going to try and break out two two zero zero item repeat two two zero zero item tonight three zero July Concord set watch eight two nine zero." (HMS Concord was a destroyer sent up the Yangtze to support Amethyst's escape.)

A lot of people still think that the security that OTPs offer is based on their randomness: in fact it's based on their unpredictability. In this context, the Chinese communists' knowing how the single use OTP was constructed introduced significant weaknesses. Apart from the fact than an agent in London might have been able to access the list of crew and their next of kin, column three was likely to have a disproportionate number of repeats of "Portsmouth", "Plymouth" and "London". But even if they had been able to do break and read this one message, it is likely that there would have been a time lag, and during that period they would have had to have copied and saved every single message on the Fleet Broadcast, to have been able to reconstruct the OTPs built from the dummy traffic being broadcast.

I would like to be able to say that after a carefully carried-out risk assessment an expert panel decided that the risk was worth taking, but there is no record to suggest that this was the case. It is unlikely that we'll ever know, but my guess is that this was a piece of local ingenuity, which happened to turn out well.

Ten avoidable problems which made the Royal Navy's encryption exploitable in 1939

By the time of the outbreak of war in 1939, Nazi Germany had thoroughly penetrated Royal Navy encryption systems, and the Navy's changing its main codebook caused barely a hiccough to German Navy cryptanalysts: in fact it took until 1943 to secure RN and allied naval encryption and during this time the German Navy destroyed millions of tons of allied shipping and came close to preventing the supply of food and military supplies to the UK from North America. Just as Bletchley Park exploited poor security by the German military in their use of encryption, the German Navy's B-Dienst was able to exploit the poor security of the codes used by the Admiralty. How could this have happened? A note written years later by Captain D A "Willie" Wilson RN identifies areas where the Admiralty got it wrong. I think the issues they raise are as relevant today as they were between the wars, because although security today addresses technological challenges that our forebears couldn't have imagined, the foundations of security and the mindset of the security practitioner are fundamentally the same.

The Admiralty got things so badly wrong because there was no single coordinating body managing Comsec in the UK, and no recognisable centre or standard of Comsec expertise. GC&CS had a responsibility to provide advice on Comsec to civil ministries, and could be approached by the service ministries if they so wished. Within GC&CS, just as Comint was the responsibility of Denniston, the Head, Comsec was the responsibility of Travis, the Deputy Head. However, Travis was also responsible for: collection management, for the reporting, indexing, and distribution of intelligence reports, for the GC&CS Registry, for liaison with SIS, and, from 1938, for liaison with the service ministries. All of this was in addition to his responsibility (to 'C', interestingly: not the Head of GC&CS) for the British Codes Section.

The fundamental problem was that nobody questioned the principle that good cryptanalysts would make good communications security advisors, when in fact their advice would be limited by the extent of their cryptanalytic skills. In a non-mechanical environment, this meant cryptanalysts saying "this is the sort of code I can't break", and assuming a) that that meant that nobody else would be able to, granting that code an invulnerability; and b) given that cryptanalysts didn't do traffic analysis, that crypt security was the only security that mattered: that wireless security (secure traffic management) wasn't something that needed to be considered.

1. Don't split responsibilities among different people.

The Director of Naval Intelligence (DNI) was responsible for technical and physical security, but was dependent on technical cypher matters on the advice given by GC&CS. The Director of the Signal Department (DSD) was responsible for providing the means of communication, and for providing the Coding Staff, but he had no responsibility for wireless security, (ie for denying the enemy intelligence from traffic analysis). The Paymaster Director General (PDG) had responsibility for the provision and training of cypher staff, but had no responsibility for the cyphers used.  In the Fleet the Secretary to a Flag Officer was the Squadron or Fleet Cypher Officer, responsibly for seeing the proper use of cyphers afloat. Within the Admiralty M Branch of the Secretariat was responsible for the distribution of Cyphers and Codes through the Navy, and the Secretariat provided the Admiralty cypher office, known as "War Registry".

2. Choose your advisers carefully

GC&CS was required to advise (but not mandate) security to the services between the wars. In fact Travis advised the Admiralty, Tiltman advised the War Office, and Josh Cooper advised the Air Ministry, but they didn't talk to each other about security, and didn't consult any of the rest of the cryptanalytic staff in GC&CS. Their advice was, therefore, strictly limited. Cipher security was the subject of a lecture on the Accountant Officers Technical Course (a prerequisite for a Secretary to a Flag Officer) but by the beginning of the 1930s this was a lecture about cryptanalysis given by Bodsworth and Knox, and was unlikely to have been illuminating. The Long Signal Course for officers specialising in communications had no lectures at all on communications security.

3. Know when to ask for a second opinion

The key piece of advice that the Admiralty needed was about the security of the 'Long Subtractor', the key used to encipher messages once encoded. In effect, this was a one time pad which was reused. How many times could it be reused without compromising security? Theoretically, it should never be reused, but in practice, could it be? Wilson wasn't happy with the response: once gave absolute security, twice was almost guaranteed, three times wasn't really dangerous, but more than three was, and using the same piece of key five or six times was positively dangerous. This was very bad advice, and Wilson knew it, but there was no move to change advisor (nor any obvious other advisor to turn to).

4. Security doesn't come second to intelligence

The Admiralty had two billets in GC&CS for officers: the idea was that this would be a source of officers with practical experience in security. But everyone in GC&CS knew that the department's main job – its important job – was intelligence production, and the officers posted in became, for the most part, cryptanalysts. Intelligence breakthroughs are of tremendous value: if your security is no good, it will be your adversary who makes the intelligence breakthrough by exploiting your communications.

5. Don't do the enemy's job for him

The RN used three different basic codebooks: Tactical Code (3 letter groups, not reencrypted); Administrative Code (five figure groups, reencrypted with a Long Subtractor); Naval Cypher (used for operational traffic: four figure groups, reencrypted with a  Long Subtractor). This meant that anybody intercepting a naval message immediately knew, without decryption, what sort of message had been sent. And although different Long Subtractor tables were used for different regions and commands, the indicator – the explanation of the start point in the relevant table – wasn't disguised at all. The German Navy's cryptanalysts had it easy.

6. Don't assume before you understand

In order to gauge how many of each reciphering table to print and distribute (a job that would always be complex given the Navy's worldwide extent) the Admiralty had to make assumptions. It assumed that the proportion of administrative to operational traffic in wartime would be around 80:20 – they were wrong: it was the other way round. If the Royal Navy officers in GC&CS had been doing the job for which they had been posted in, they would have seen this by looking at traffic levels in Italian Naval material collected for GC&CS during the Abyssinian Crisis and the Spanish Civil War.

7. Even if it ain't broke it might still be worth fixing

According to Wilson, by 1937 when Typex, the UK version of Enigma, came into service, Lord Mountbatten was pressing for it to be used by the Royal Navy but got nowhere because of the lack of a single person able to resolve to bring a new encryption system into use. Lord Mountbatten concluded that it was just too difficult, but even putting Typex on a few ships in the North Atlantic could have made a tremendous difference. I asked the Duke of Edinburgh about this in 2013 and he confirmed it. (That is probably the most outrageous name drop you'll see today.)

8. Who needs what?

As a matter of routine, Commands, shore establishment and major ships were given copies of all reciphering tables, so that anybody could communicate securely with anybody else. But why (for example) would CinC Nore need to communicate securely and directly with the Senior Naval Officer Upper Yangtze? Why couldn't the few (I imagine) messages between most territorial commands not be relayed through the Admiralty. Apart from the difficulty of printing and distributing so much key material, it meant that if a ship was believed to have potentially been captured by enemy forces, all key material on board had to be assumed to be compromised.

9. Understand the vulnerability of your mode of communication as well as of your crypto

After Wilson had been Head of a new section NID10/DSD10 in the Admiralty early in the war, he set up a new section to look at the way the Navy communicated to see whether the Germans might be able to derive intelligence from analysis of the traffic. This had never been done before.

10. Security versus Operability

Security and operability don't always have to be in competition: designers of systems need to understand how users communicate to design practicality alongside security; system administrators need to ensure that the reasons for the rules they impose are understood; and users mustn't try to subvert the rules and compromise security simply to make life easier. In order to make Royal Navy comms practice secure against German traffic analysis, DSD10/NID10 introduced a series of security measures without explaining them to the signalmen who had to implement them. As a result, they were widely ignored and subverted. When this was discovered the signalmen asked for a senior officer to investigate the matter. Admiral Somerville (who had been in charge of wireless comms for the Mediterranean Fleet during the First World War) was asked to do this and he came down firmly on the side of security, but was able to explain why to the signalmen, from whom there was no further opposition to the new measures.