by Leo Marks
I escaped from Vercors by spending the next eight hours attacking our first indecipherable from a Jedburgh. It had been transmitted by Andy in his one-time pad, and had already defied three blanket attacks and my so-called guidelines.
Eleven hundred failures later I threw the pad on to the floor in disgust and discovered that instead of starting on page one of his pad he’d started on page six, a major cryptographic breakthrough. (I subsequently learned that he’d detached page six so that he could always have a sheet of his pad with him and had decided to use it before it became too crumpled.)
His message made disturbing reading, if anything could be after Vercors. Two members of his team had met with accidents on landing and had broken three legs between them.
Eleven other Jedburgh teams were also operating in France, and their encoding was flawless. (One message stated, ‘We’re now sitting and waiting,’ which puzzled the Jedburgh section but which I took to be a reference to our Milton Hall encounter.)
No longer quite so ‘damn insular’, thanks to Commander Two Ns, I noticed that the attempt to merge our rival French sections under Koenig had only driven them further apart, whereas the fusion of SOE and a branch of the OSS into SFHQ had had the opposite effect.
The Americans were more co-operative than ever and had supplied us with large quantities of silk, which we badly needed to produce new codes for the Middle East and Burma. Their eagerness to help in every way they could may have been due to the difficulties we suspected them of having with Sussex (their intelligence-gathering operation with C), though they never referred to them. And under the leadership of Captain Phoenix their code room at Station 53c had quickly mastered the complex re-encipherment drill and had developed a character of its own, as any good code room should.
I became totally absorbed in trying to speed up the three-way system and was surprised when Nick ordered me to report to his office immediately. I was sitting rigidly at his desk with Heffer only a puff or two away. Whatever they’d been discussing had drained the room of air.
‘What I have to tell you is highly confidential.’ With a quick glance at Heffer, he extracted three documents from a Top Secret folder. ‘These mustn’t be discussed outside this room …’
He seemed uncertain how to proceed or even whether he should, but finally said that three messages in code had been intercepted and the only thing he could tell me about them was that I had to break them as quickly as possible. ‘The last message is incomplete,’ he added.
So was his summary. He’d said nothing about who’d sent the messages, who’d intercepted them or why they were in his possession, and Heffer’s expression warned me not to ask.
I was finally allowed to look at them. ‘It’s obviously a substitute code of some kind – any idea what language they’re in?’
‘Possibly Dutch.’
‘From an agent, sir?’
‘To one more likely … They may have been sent, I repeat may, by the Dutch government-in-exile.’
I received another silent warning from Heffer to ask no more questions.
Nick then instructed me to choose six coders from London or the stations to help me break them. They’d work in a room next to the Signals Office to which only he, Heffer and I would have access, but on no account must they know what they were working on. ‘You’re to tell them that we’ve been asked to help break some important German messages which they’re not to discuss with anyone.’
He seemed to think the meeting was over, but I suggested that a Dutch linguist might be useful and was sharply informed that he or she would have to be a member of the Signals directorate, as no one else in SOE must know what we were doing.
Heffer then made his first vocal contribution. ‘The messages may contain place names, so a few maps might be handy …’
His face was the only map I could rely on, and it warned me to ‘get cracking’.
I chose three coders from London and three from the stations, and a rumour spread throughout the Signals Office that Mr Marks was forming a team to break Hitler’s secret diary.
But before putting the girls to work, there were some questions to be answered.
Why did Nick suspect that the messages were from the Dutch government-in-exile? He was in touch with his former colleagues in Y, who’d almost certainly intercepted them. Could it be they who’d told him? And had the government-in-exile got SHAEF’s permission to send messages abroad and been allotted special frequencies?
The person who’d know all about the frequencies, and who was also in touch with Y, was Gerry Parker, the head of Signal-Planning. I questioned him without disclosing my reasons or mentioning the government-in-exile, but Gerry had his own antennae and seemed to sense what I was after. Or perhaps he already knew.
He told me that the ‘Dutch bastards’ (with him a term of endearment) could communicate with the Netherlands any time they wanted to by getting messages to their fleet, which would have no trouble transmitting them according to instructions. He was convinced that they’d frequently been in touch with Philips of Eindhoven, who could easily receive their messages because of the huge quantity of radio equipment they were manufacturing. He had no doubt about their objectives: ‘They’ve got millions of guilders at stake and want to protect ’em. They’re more concerned with playing politics than winning the war, like the rest of the bastards.’
He left to continue playing them himself.
I still didn’t know why the messages were important, or why Nick didn’t send them to Bletchley, or why he wouldn’t tell me who’d intercepted them.
But of one thing I could be certain. It was time to ‘get cracking’.
The first message was fifty letters long, the second fifty-five and the third (which Nick had said was incomplete) only twenty. The first step was to take a frequency count of the individual letters, then of the bigrams (or pairs of letters) and finally of the three-letter combinations.
The girls, some of whom had come armed with German dictionaries, set about the tedious task (which Bletchley probably did by machine) as if they were embarking on an early-morning run. It became increasingly uphill.
The frequency count confirmed that a substitution code had been used, and it seemed safe to assume that with millions of guilders at stake the government-in-exile would use one-time pads, and I proceeded on that basis. And got nowhere.
After three days of trying every permutation I could think of, the girls had lost all confidence in me, and I was pleased with their good judgement.
There was no sign that the messages had been enciphered on the same code groups, which would be our only hope of breaking them, and I was more than ever convinced that this was a job for Bletchley, whose cryptographers didn’t need to drop one-time pads on the floor to achieve their results.
I was now on the floor myself, with my self-esteem more crumpled than page six of Andy’s LOP. The only other time I’d felt as low as this was when I’d failed to find a way to set a trap for Herr Giskes, and I suddenly remembered how the solution had finally come.
I’d gone to 84 and sat in the chair once occupied by Freud when he was writing Moses and Monotheism, and the idea of sending Giskes a deliberate indecipherable had popped up from the unconscious, the greatest of all code rooms. Hoping that 84 would provide another miracle, I returned to Freud’s chair without leaving my office and remembered what else had happened.
He’d been shown every book on Moses that Marks & Co. had in stock, and I’d read one which had particularly interested him. I hadn’t thought about it since, but closed my eyes and did so now …
When Moses was rescued from the bulrushes by his adoptive mother, she was forced by law to take him in front of Pharaoh, who was determined to find the infant king of the Jews and kill him. To test the baby’s credentials, the high priest held out the crown jewels of Egypt to Moses with one hand and a brazier of burning coals with the other.
The infant stretched out his hand towards the jewels, but the Angel of the Lord gui
ded it to the brazier, and he put the burning coals in his mouth.
Pharaoh was convinced that no king of the Jews would make such a mistake and allowed the infant’s adoptive mother to remove him, but Moses spoke with a stammer for the rest of his life.
According to George Plummer, Freud interpreted the incident as a symbol of oral penetration and used it to develop his theory that Moses and Aaron had a homosexual relationship.
I opened my eyes and discovered that my hand was resting on something. Had it been guided there by the Angel of the Lord?
It was a copy of an agent’s Playfair code, an elementary system suitable for concealing brief messages in ‘innocent letters’ but for very little else. It was marginally more secure than invisible ink, and even Duke Street knew better than to use it for WT traffic.
Only a novice angel would suggest that Playfair was my burning coals. Yet was I being the novice? … Could Playfair be the answer? It would explain the lack of indicators, the frequency of the consonants and the repetition of the bigrams. And it was possible that the three messages had been enciphered on the same Playfair phrase.
I hurried in to the girls, who were less than pleased to see me. Doing my best not to stammer, I said that there was one last thing to be tried.
‘Our patience,’ one of them whispered.
I showed them how to break Playfair (it was just tricky enough to interest them) and then hurried away to see what else the Angel could do for us.
But no miracles occurred, and after slogging away for twenty-four hours without the slightest success I began cursing 84, Freud and those poofters Moses and Aaron. I was about to tell Nick that he needed to consult Tiltman, when the telephone rang.
It was the team supervisor, but I could hardly hear what she was saying above the babble in the background. One of the girls thought she’d found a German word, but the linguist was convinced it was Dutch.
She was right.
Two hours later the messages were en clair, and the cheer that went up in the code room could have been heard in the Netherlands.
I marched the jubilant code-busters into Nick’s office and carried the broken messages aloft as if they were the Torah.
His face blessed us. As we left he was reaching for the telephone.
I still didn’t know what the messages contained, as my Dutch was on a par with my Egyptian, and the girls were too elated to care. But it was Heffer who was responsible for the breakthrough: the messages contained several place names, as the Guru had suggested.
All of them were new to me, and I looked them up on the map in case they cropped up again.
One of them was a town called Arnhem.
SEVENTY-FIVE
The Day of Reckoning
By mid-August the outcome of Overlord was no longer in doubt, least of all to the Germans. The Allies had begun pushing them back towards the frontiers of their Fatherland, the French had ensured that entire divisions never reached it and showed them what was meant by a National Uprising, and de Gaulle was expected to arrive in Paris within the next few weeks.
The code department had also made an advance or two. We’d produced over twenty million one-time pad groups, over 750,000 transposition keys and over eight thousand code books. We’d also re-enciphered over four thousand three-way messages.
But despite all this (and perhaps a little more) there was one country section which had made no demands on us whatsoever, whose traffic (if it passed any) we hadn’t handled and whose plans were completely unknown to us. Yet it was potentially the most important country section in the whole of SOE: it was responsible for the infiltration of agents into Germany and was known as X section.
It was run by a major named Field-Robinson with the help of two assistants, but I knew them only by their symbols (AD/X, AD/X PA and AD/X1 respectively). I knew even less about their activities, which appeared to be non-existent, yet if they intended to operate inside Germany they’d need WT sets, signal plans and codes unless they proposed to send their messages by carrier pigeon.
I raised the question with Nick, who’d been unusually forthcoming since the breaking of the three Playfair messages, and he explained the mystery of X section’s silence at greater length than I’d expected.
The decision not to infiltrate agents into Germany had been taken by Hambro when he was CD. He was convinced that security in the Fatherland was so tight that large-scale operations would end in disaster and that the infiltration of individual agents would achieve nothing.
Gubbins had agreed with this view, much to C’s relief, as many of their peacetime agents were still operating in Germany and Austria and they didn’t want SOE’s saboteurs to cause even tighter security measures and thus blow their established agents (one of their principal complaints against us in the rest of Europe). But the OSS took a completely different view and had the power to enforce it. They planned to infiltrate agents into Germany and Austria via Switzerland, Italy and Yugoslavia. X section’s function would be limited to supplying them with contacts and the benefit of their inexperience.
Nick added that their first joint op was code-named Downend and was already being mounted. It was on a very small scale, and no WT communications were involved.
I’d listened in silence until now. ‘Won’t SOE ever operate inside Germany?’
He looked at me with a trace of his old wariness. ‘Not unless the policy changes, but stop worrying. One day your codes will be used inside the Fatherland, I assure you of that.’ He smiled at me from the power base of his secret knowledge, and the briefing was over.
A sure sign that France was about to be liberated was the number of senior officers who were anxious to leave Baker Street and join Special Forces Advanced HQ. They knew that de Gaulle’s re-entry into Paris was imminent, and wanted to be there to make him feel at home.
They made a surprising request of the Signals directorate: they wanted to understand the workings of our three-way communications and had asked Nick and me to brief them. He’d agreed that he’d deal with the WT aspects and that I’d fill them in about codes.
I certainly intended to fill them in, but not in the way they expected.
I followed my leader into a packed conference room, and the first people who caught my eye and returned most of it were the ‘hard men’ (George Courtauld and Tommy Davies), without whom we’d have had no silks. They were flanked by Harry Sporborg (Gubbins’s right hand) and by Mr Murray (who’d shared my office for a week and was now Gubbins’s left hand). Group Captain Venner (head of Finance) was also in the front row totting up expenses.
I wasn’t prepared for such a collection of powerhouses and sensed that there was more to this meeting than I’d realised, but nothing was going to deflect me from my intention, which I hadn’t disclosed to Nick.
He mounted a small platform at the end of the room and, despite his lumbago and his preference for giving lectures on a one-to-one basis, spent the next twenty minutes describing the signal plans, WT sets and procedures which had made our three-way communications possible. Speaking from notes without looking up, he appeared not to notice that many of his audience had begun producing symptoms of mental lumbago.
But he still wasn’t ready to end his sked. Turning his attention to codes, by no means his strongest subject, he spent another five minutes describing the innovations ‘Marks has introduced’ (some of which I recognised) but suddenly seemed to remember that he hadn’t arrived unaccompanied and turned aside to let me take over.
I’d waited two years for this moment. There were many officers present who’d insisted that agents must re-encode their indecipherables if we’d failed to break them in time, and this was the day of reckoning.
I mounted the platform, and all the girls who’d stayed up night after night trying to break those indecipherables against the clock stood beside me, red eyes, periods and all. I pulled the covers off my customary prop, and those still awake stared with disinterest at the two encoded messages which had been written on the blackbo
ard in my own unfair hand.
But these were no ordinary messages. They were real indecipherables which had arrived from a Buckmaster agent a year ago, and which had taken us over eleven thousand attempts to break. They’d been encoded on the same transposition keys, and the only alteration I’d made was to shorten one of them to make their lengths identical.
Trying to keep the anger out of my deep brown melter, and restraining the impulse to start, ‘Listen, you bastards, if you can remember how to’, I explained what the messages were and described what the girls had done to break them, until all our heads were reeling.
My blanket attack then gathered momentum. ‘Nick wants me to explain to you why no poem-code traffic must be passed by SFHQ.’
Nick, who’d asked no such thing, nodded emphatically.
I spent the next ten minutes explaining the weaknesses of the poem-code, probing for theirs by shooting questions at them like a schoolmaster with a recalcitrant class.
‘Nick also wants you to understand the gift you make to the Germans when you order agents to re-encode their indecipherables.’
Nick nodded again.
Pointing to the two messages, I explained the anagramming process and challenged them to call out whichever words they thought most likely to appear.
I was convinced that, with less help from me than usual, it would take SOE’s intelligentsia hours to find the right phrases. They recovered both clear-texts within twenty minutes and sat back, ready to join Bletchley. But although they’d been unexpectedly patient with me, a few of them (including Nick) began glancing at their watches.
‘There’s one last thing Nick wants you to see.’
I broke the speed limit trying to explain how the enemy reconstructed poems, then pointed to the transposition key on the blackboard and invited them to attack it. It would be more difficult than most as the agent’s poem was in French.
