GCHQ. Richard Aldrich

on French’, adding that British plans to focus on Paris ‘are going into effect at an early date’. French, Spanish, Portuguese and Latin American traffic was soon consolidated into a single group under Josh Cooper.²¹

      Major Barbieri was proud of the work of his Italian code-breakers against the French, but he pressed for more staff. So many of the best cryptographers, he complained, had been captured by the French in North Africa, adding, ‘the French are now employing them in their own service!’ Nevertheless, the British concluded that the Italians were ‘doing remarkably well with the limited reserves at their disposal’.²² By mid-1946 they were giving them new tasks, including Soviet traffic which came from military cypher machines at division level code-named ‘Taper’. British liaison officers with the Italians were working closely with code-breakers in Britain on the identification of new Taper groups. Senior Italian sigint officers knew that Taper traffic ‘which had been taken with so much depth and continuity for the past month’ was Soviet in origin, but many of their underlings were in a state of blissful ignorance about what they were collecting and who the ultimate customer was.²³

      The efforts of TICOM were not exclusively directed towards raiding priceless sigint secrets from the Germans, the Italians and the Japanese. They were also concerned with protecting Britain’s own secret communications. Until late 1943, Bletchley Park regarded weak security as a problem restricted to Britain’s allies. But the ability to read German messages had revealed a number of unexpected security nightmares for the Allies. Ultra had shown Britain’s code-breakers that the Germans could read many of the codes of the Allies, such as those of the Soviets and the Free French. In Asia, terrible cypher security and serious human agent penetration ensured that Chinese codes were effectively an open book to the Japanese, even though Tokyo’s code-breakers were mediocre. Accordingly, keeping Britain’s secrets safe meant keeping them away from many of her allies, whose communications were being read by friend and foe alike.²⁴

      By the autumn of 1943 the security situation looked much worse. The Italians had now capitulated, and captured Italian code-breakers revealed their successes against British codes. Captain Edmund Wilson, who helped to look after cypher security at Bletchley Park, held prolonged ‘conversations’ with Commander Cianchi, head of the Italian Cryptographic Bureau in Rome, and his staff during late 1943. Wilson explained that he could hardly call them ‘interrogations’, since Cianchi had given all of Italy’s secret information so happily and freely. Wilson said that ‘very valuable information’ on the breaking of British naval cyphers had been obtained, and that Britain was ‘extremely fortunate’ to have the cooperation of its former opponents. He pressed his colleagues to be ‘very careful indeed in the use they made of the information’ from these sources.²⁵

      The TICOM raids into Germany later confirmed that British naval cypher security had been especially weak. B-Dienst, the German naval sigint service, had been reading British naval codes and cyphers easily at the start of the war. In early 1940 this had allowed it to read British plans for the Narvik raid in Norway, contributing to Germany’s success in repulsing that action. In 1942, the Dieppe raid had also been given away to the enemy before it took place due to poor cypher security. Incredibly, the Germans had been given a full five days to prepare for this ‘surprise attack’. Allied troops – mostly Canadians – paid for this dearly in the slaughter that followed. B-Dienst achieved the height of its success against Atlantic convoy traffic in 1943, allowing alterations of convoy routes to be radioed to U-boat commanders within a few hours.²⁶

      The autumn of 1943 saw a long-overdue inquiry into the security of British cyphers, carried out by Brigadier Chitty, who began by visiting Bletchley Park. His findings did not make for comfortable reading. ‘It is true,’ he reported, ‘that of the fourteen sections working at B.P. [Bletchley Park] one is named Security of Allied Communications. From a total staff of some six thousand, however, the part-time services of only one man (Dudley-Smith) plus two or three girls, are spared to equip this section.’ At a higher level there was a supervising body called the Cypher Security Committee, supposedly chaired by Sir Stewart Menzies, but this had not attracted Menzies’ interest. Moreover, it lacked the power to compel Whitehall departments to change any practices that they thought lax. Chitty had done a spot check of twelve departments around Whitehall, and found that few were taking cypher security seriously. Britain needed a decent operational security section at Bletchley Park, and a proper supervisory board with teeth.²⁷

      No cypher system, Chitty warned, was unbreakable. Britain’s most sensitive material was sent by one-time pads, which were, in his opinion, ‘unassailable’ if used correctly. Yet he reminded his superiors that Bletchley was making a ‘most successful daily attack’ on the one-time pads of other countries, ‘which reach us in a steady stream by Photography, Theft, and the sifting of Embassy waste-paper baskets’. The majority of London government traffic went by Typex machine, the British equivalent of Enigma. This was much better than Enigma, but Chitty asserted that its security had never really been tested. Again, much depended on the diligence of the operators:

      One of the most instructive lessons I learnt from the [Government Code and Cypher] School was the fact that the Hagelin machine used by several nations including the Americans, affords in practice a widely different degree of security in different hands. Whereas this machine, as used by the Swedes and the Finns, has so far been virtually unbreakable, in the hands of the Italians who are normally very good cryptographers, we have for a long time been able to read it with ease. This was entirely due to the increasing idleness of the Italian operators and their persistent disregard of the numerous security rules which have been laid down for them.

      For routine traffic the Foreign Office used more elderly hand cyphers, and the services made use of field cyphers in their lower formations. Quite rightly, these were thought to be even less secure.²⁸

      By March 1944, no less a figure than Winston Churchill himself was calling for a shake-up. A new supervisory outfit was created, called the Cypher Policy Board. Although Menzies was in the chair, Edward Travis from GC&CS, together with the Secretary of the War Cabinet and a representative of the Chiefs of Staff were also there to keep a stern eye on him. This top-level representation underlined a deep anxiety about cypher security. A new Deputy Director of GC&CS, known as the Communications Security Adviser, was also to be appointed, who would serve as the Secretary of the Cypher Policy Board. In reality, this person, Captain Edmund Wilson, was the new broom.²⁹ After the war, Wilson was replaced by Commander T.R.W. Burton-Miller, who operated from a new headquarters at 10 Chesterfield Street W1, conveniently close to both MI5 and SIS.³⁰ Soon they had extended their authority over the design and production of all British cypher machines, with Gordon Welchman their chief technical adviser.³¹

      During 1944, Bletchley Park offered an impressive technical solution to worries about cypher security. It fielded a new and rather superior cypher machine called ‘Rockex I’ that produced what was effectively automated one-time pad traffic. Instead of using tiresome tear-off sheets from a one-time pad that had to be processed by hand, it used code tape, which carried the same information. This was initially used for messages between Bletchley Park and its sigint collaborators in Washington and Ottawa, together with the SIS wartime office in New York. A new version called ‘Rockex II’ was already being developed by the British. The machine was originally intended for the Special Communications Units that disseminated Ultra to Allied commanders in the field, but after the war it became a mainstream British cypher machine, and was still being used by smaller embassies in the 1970s.³²

      The super-secret Rockex cypher machine also had another purpose.