Dilly

by Batey, Mavis;

  Fortunately, it was the Italians who came to the rescue and proved that it was real after all. The Germans had always accused the Italians of having traitors in their midst, which was made worse when, in 1966, H. Montgomery Hyde published the story of the beautiful spy Cynthia, who was alleged to have seduced the Italian naval attaché in Washington and obtained the codebook from him which resulted in the defeat at Matapan:

  Cynthia’s first major assignment, in which she won her spurs during the winter of 1940–41, was to obtain the Italian naval ciphers from the Italian embassy in Washington. She began by securing an introduction to the naval attaché, Admiral Alberto Lais, whom she lost no time in cultivating assiduously. He responded to her charms in the manner she desired, and soon within a few weeks of their first meeting he imagined himself deeply in love with her. As a result she was able to do with him virtually what she pleased. In retrospect, it seems almost incredible that a man of his experience and seniority, who was by instinct, training and conviction, a patriotic officer, should have become so enfeebled by passion as to be willing to work against the interests of his own country to win a woman’s favours. But that is what happened. As soon as she had him where she wanted, Cynthia came straight to the point. She told the admiral that she wished to have copies of the naval cipher. Astounding as it may appear, he agreed without apparent demur to assist her.

  As one reviewer observed, ‘treason in bed and death at sea made a libretto which sold well’ and the admiral’s family felt obliged to take out a libel action, such a course being permitted in Italy on behalf of the dead. Montgomery Hyde was found guilty but the real evidence to clear the admiral was not then available. All went quiet until Winterbotham’s book appeared in 1974. The Italians were delighted as it paid off an old score by proving, as they thought, that it was the German and not the Italian signals which had forewarned Cunningham about Operazione Gaudo. They wanted to have The ULTRA Secret translated and published at once. However, Dr Giulio Di Vita, a fellow of Clare College, Cambridge, who was asked to edit the book, was determined to investigate the matter more thoroughly than Winterbotham, who was no historian. When records were released in 1978, Di Vita found plenty of evidence that it was in fact Italian and not German messages that had given the game away, but was forbidden to publish his findings. However, he became aware that Ronald Lewin had also seen the public records and was writing a book on ULTRA in 1978, which for the first time would show the part played by Dilly’s section in the Battle of Matapan from declassified records, which had not been available to Winterbotham.

  Now it was official that the Italian ciphers had been broken, but when the BBC ran a series of TV programmes called Spy! in 1980, the story of Cynthia was rehashed. After all, they alleged, it was she who sent the codebooks to the Admiralty, which allowed the signals to be read. Di Vita was incensed and wrote to The Times about the misrepresentation of the facts, having by then decided to track down the real Bletchley Cynthia, or at least one of them. I was sent a glowing account of the interview in an Italian newspaper referring to me as an ‘affascinante signora, il tipo Penelope Keith’ in her ‘bella casa di Oxford’. At least I was able to scupper the idea that we had been given codebooks by Cynthia or anybody else; if we had had such books, machinists would merely have had to put the key settings on the simulated Enigma machine without any need of codebreakers. It was then, having seen the letter in The Times, that ‘Nobby’ Clarke’s son wrote in to say that he had been on duty the night the message was received: ‘Tell Dilly we have had a great victory in the Mediterranean and it is entirely due to him and his girls’.

  Unfortunately, the secretary of His Honour Judge Edward Clarke (as Nobby’s son now was) had typed ‘guts’ for ‘girls’ and an urgent note followed, ‘for guts, please read girls’. Dilly would have loved it. At last, the evidence was available for the courts to exonerate poor Admiral Lais and I was asked whether, if they brought the Matapan messages, I could testify that they had been broken cryptographically. I warned them that as it was forty years ago there wasn’t much chance of my remembering the actual break. Nevertheless, losing no time, Di Vita brought the admiral in charge of naval history over from Rome and, when I picked up the first long message headed SUPERMARINA, it seemed that time had stood still and I was nineteen again and wearing a green jumper. It had been raining all day and it was still pelting down when I rushed it over to the hut, where Dilly, as I now know, was securing ULTRA treatment for its transmission. Cynthia was finally put to bed; no seduction and no codebooks but just hard cryptographic slogging by Dilly’s girls. On his return to Supermarina, my new admiral friend wrote a charming letter of thanks, but with the lesson of Cynthia still in mind, he ended on a cautious note: ‘Hoping to be given the opportunity of meeting you again on work matters.’ Perhaps Dilly should have the last word on Matapan in his epitaph to Mussolini:

  These have knelled your fall and ruin, but your ears were far away English lassies rustling papers through the sodden Bletchley day.

  TEN

  Dilly and the Spy Enigma

  Dilly’s greatest triumph in cryptography and intelligence, which for him were always inseparable, was the breaking in October 1941 of the Enigma machine used by the German military intelligence service, the Abwehr. Little was known about the Abwehr organisation before the war. In March 1940, two members of the Radio Security Service (RSS), charged with intercepting illicit wireless in the UK, broke some simple hand ciphers from a Hamburg-controlled station, which at first aroused little interest. Finally Hugh Trevor-Roper and E. W. Gill, the latter a leading member of the Army’s First World War codebreaking organisation, had succeeded in attracting Bletchley Park’s attention and Oliver Strachey was asked to set up a section to be called Illicit Services Oliver Strachey (ISOS) in Elmer’s School to research this traffic. By December, Strachey had broken the main hand cipher, enabling Bletchley to give MI5 advance warning of the arrival of German spies. These individuals were rather different from the disorganised refugee fifth columnists I had inadvertently befriended in 1938, when there was still free access across the Channel. It was now apparent that the Abwehr was operating a considerable professional espionage network across Europe.

  After the fall of France and Hitler’s plans to invade Britain, Operation Sea Lion, were drawn up, the agents being infiltrated were meant to be an advance guard to wait for the arrival of German troops and to report on morale. However, in 1941, when the threat had receded, there was a reorganisation of our security and the RSS (largely still amateur ‘ham’ wireless enthusiasts) was put under direct control of SIS. Dick White, a future head of both SIS and MI5, covering both espionage and counter-espionage, suggested that captured agents should be left in place and ‘turned’ to work as double agents. Camp 020 was set up for interrogation at Latchmere House, Ham Common, Richmond, to identify suitable double agents who could send back false information to their unsuspecting controllers.

  MI5 managed the controlled agents and a London clearing house was set up to co-ordinate operational activities; it was known as the Twenty (XX) Committee, hence Double Cross, under John Masterman, a future vice-chancellor of Oxford University. The double agent was to send out his false information on his wireless transmitter as directed by his case officer, using his own hand cipher given to him by the Germans. Their controllers in neutral capitals, mainly Lisbon and Madrid, would receive and analyse the messages before transmitting the information to Berlin on the Abwehr Enigma machine.

  Before this high-grade Enigma traffic was recognised for what it was and thought to be on the services machine, it was sent to Gordon Welchman in Hut 6 but he could make no headway and it was given to Dilly as unknown Enigma research. After Matapan the Italians mostly used their Hagelin machine; the Enigma machine traffic was infrequent and was turned over to routine production outside the Cottage, so that Dilly was able to give the Abwehr material his undivided attention. The Knox family had always been fascinated by spies and Kim’s ‘Great Game’. Dilly spen
t some time over at the School with his friend Oliver Strachey (the brother of his good Cambridge days friend Lytton) learning about the organisation of the Abwehr. First of all the many different spy networks had to be sorted out covering Spain, Portugal, the Balkans and Turkey to see how the ISOS hand-ciphered messages related to Dilly’s Enigma messages sent on from the neutral capitals to Berlin after December 1939. It was hoped that there would be good cribs from the previous hand-cipher traffic, which Dilly studied carefully. One member of Strachey’s section, who was proving to be very skilled at breaking ISOS hand ciphers, was Denys Page, a kindred spirit for Dilly as he was also a scholar of Greek poetry and interested in the Oxyrhynchus papyrus texts. Page would succeed Strachey as head of ISOS in 1942 and would collaborate with Dilly’s friend Edgar Lobel in publishing literary papyri after the war.

  At this stage, however, Dilly’s easy-going relationship with ISOS had not been officially approved. Dilly kept Denniston informed of his progress on the Abwehr Enigma machine but Denniston, with his obsession for secrecy, seemingly disapproved of the way he was going about things. Denniston’s success about keeping secret his own activities in signals intelligence is shown by the Venlo incident. The Schellenberg document on the British secret service following the interrogation of Richard Stevens states that the head of the cipher and decipher section is unknown and implies that he ran a code-making and not a codebreaking department. Denniston knew how essential it was not to let the Germans know that their messages were being broken as the whole signals intelligence system which had been gradually built up would be lost. ‘Need to know’ restrictions were strictly enforced, but it is difficult to understand why Denniston considered that Dilly had no ‘need to know’ about ISOS, which was obviously so relevant to his work. Infuriated, Dilly sent Denniston a fierce note, again threatening resignation over what he saw as a ridiculous ‘hush-hush’ policy imposed by Denniston – almost certainly on the insistence of SIS – that prevented him seeing material which would help him break the Abwehr machine.

  My dear Denniston,

  As you, I think, are aware I have decided to attempt a scheme for the reconstitution of one or more outlying German Enigmas. Before proceeding further in the matter there are one or two points, relevant either to the matter itself or to my examination of points of attack, on which I must press for your assurances, and failing these, for your acceptance of my resignation …

  In the event of success the whole traffic must be handled in ‘The Cottage’ or our nominees. This is a fundamental point in all research of an academic nature. Research, in fact, does not end till the person responsible has affixed his imprimatur on the last proof sheet …

  We still have far too many intelligence sections, appearing to the casual observer, as mangy curs fighting over whatever bones are tossed to them, and (as far as circulation goes) burying their booty in grimy and schismatic indexes. Yet what they get is the material which assists the cryptographer in his researches and this he is wholly unable to see. Occasionally someone may hand him a slip of paper with references to a buried file, but this is not wanted. As in Broadway, he wants the document, all the documents, and nothing but the documents …

  These burials of essential documents are, I believe, made in accordance with your policy of ‘hush-hush’ or concealment from workers in Bletchley Park of the results of their colleagues. Against this I protest on several grounds … Such action cripples the activities of the cryptographer who depends on ‘cribs’ … Such action wholly destroys any liaison or pride in the successes of colleagues …

  I would urge with the utmost assurance that your action in directing any acts of concealment in Bletchley Park is wholly unconstitutional and ultra vires. Under the Official Secrets Act, I may discuss my work with anyone in the course of my duty. Of this I am the only judge, but it may perhaps be limited to the time of my arrival at, and departure from Bletchley Park. Outside Bletchley Park you may authorise me to discuss with anyone or refuse such authorisation. That is your constitutional prerogative.

  When Dilly knew that he was near to a successful break, he wanted to know how the intelligence from the messages would be dealt with before the inevitable flow-chart appeared indicating who was in charge of what. Another letter to Denniston, a mixture of under- and overstatement says it all. He speaks of a ‘minor ailment’, which is why he is away for a few days; it was in fact a secondary cancer but few people were aware how ill he was. He wants to know where he stands and to try to ‘establish an independent line as I nearly secured at Matapan’. He tells Denniston: ‘I am almost despairing of making you see reason on the major issues. You owe the present solution, for it is near to that, to my interest in enemy intelligence as a whole.’ Now apparently Denniston has a ‘monstrous theory’ that when the messages are broken they are to be handed over to ISOS as the operative unit and it will ‘now be possible for Strachey to prevent my free inspection of his other material and use of the new’, Dilly complains.

  As a scholar, for of all Bletchley Park I am by breeding, education, profession and general recognition almost the foremost scholar, to concede your monstrous theory of collecting material for others is impossible. By profession in all his contacts a scholar is bound to see his research through from the raw material to the final text. From 1920–1936 I was always able to proceed as a scholar, and I simply cannot understand, nor I imagine can the many other scholars at BP understand, your grocer’s theories of ‘window dressing’. Had these been applied to art scholarship, science, and philosophy, had the inventor no right to the development and publication of his discourses, we would still be in the Dark Ages.

  The inevitable threat of resignation unless things improved follows and the letter ends, ‘a small grouse … Yours ever, A. D. Knox.’

  Dilly’s irritation at the way in which his material was handled by intelligence officers writing reports to be passed on to the various services and government departments was a recurrent theme in his complaints. In a letter to Menzies, he insisted that the material should be passed on in its original format. ‘In my opinion, Bletchley Park should be a cryptographical bureau supplying its results straight and unadorned to intelligence sections at the various ministries,’ he said. ‘At present we are encumbered with “Intelligence Officers” who maul and conceal our results yet make no effort to check up on their arbitrary corrections.’

  Above all, Dilly wanted to be in on the overall intelligence and suggested that heads of sections should be issued with regular bulletins with headings ‘Enemy Operations, Enemy Intelligence, Enemy Codes’. In anticipation of his wish being carried out, he went over to see his old friend Professor Edgar Lobel to discuss whether he was free to leave Oxford. As a former keeper of Western manuscripts in the Bodleian library, and as editor of the Oxyrhynchus papyrus texts, Lobel was renowned for his critical intelligence and concise abstracts. For good measure his wife, who was an editor of the Victoria County History, impeccable on sources, could accompany him. ‘She is a very nice and remarkable woman of the donness class,’ Dilly told Denniston. Although the double Lobel scoop did not materialise, Dilly must have been satisfied with Denniston’s circulation arrangements as the next communication with him was the report on the breaking of the Abwehr machine, dated 28 October 1941, and a request for the increase of Cottage staff.

  Hopes of reliable cribs from ISOS messages, given that the messages encoded on the Enigma machine were a version of the actual text dictated to the double agent by the British case officer, had soon been dashed; but it was not immediately clear to Dilly why. However, once the various networks and their message indicators had been sorted out Dilly found the successful way in to breaking this unknown Enigma variation without textual cribs. Fortunately, nobody seemed to have told the Abwehr of the danger of having repeat indicators on a fixed Grundstellung, which the services had abandoned as long ago as 1938. Instead of three-letter indicators as in the services Enigma, Abwehr was seen to have four, the same number as the ‘K’ Enigma,
which meant that there was a settable Umkehrwalze. When Dilly embarked on making key-blocks he found that the number of messages on any one day in a network was insufficient for evaluation and the boxing chains were too fragmentary to be of use. He decided, therefore, that if he could find two days where the same wheel order was used, and in such a way that the Grundstellung from one day could be got from rotating each wheel and the Umkehrwalze through the same number of places, he would be able to double the number of indicators on the key-block. This would be observed because the cipher pairings at each position of the Grundstellung would have a QWERTZU substitution relationship, if indeed the diagonal was, as in the commercial machine, his old friend QWERTZU.

  Dilly accordingly went off to Hut 7 to enlist the help of Frederic Freeborn’s Hollerith card-sorting and tabulation section in searching for two such days. Then followed a true example of serendipity, as defined by Horace Walpole: ‘making discoveries by accident and Sagacity of things they were not in quest of’. Freeborn had been unable to find the two QWERTZU-related days’ settings required but when Dilly studied the results ‘he found what was wanting standing, like the abomination of desolation, precisely where it should not – on a single setting’. Then he had one of his ‘quick as lightning’ inspirations that he was dealing with a multi-turnover machine and that in one day’s key-block all three wheels and the Umkehrwalze had turned over between the first two letters of the indicator and again in its repeat position, i.e. (1) ABCD (2) BCDE (3) BCDF (4) BCDG (5) BCDH (6) CDEI. This phenomenon he called a ‘crab’, which he deemed to be useless for his purposes, but if there were four-wheel turnovers on both sides of the throw-on indicator key-block there would probably be many more cases of such turnovers on one side of the key-block alone and this possibility he called a ‘lobster’; this indeed was the brilliant idea which would break the Abwehr machine, thereafter always called the ‘Lobster Enigma’.