Between Silk and Cyanide

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Between Silk and Cyanide Page 23

by Leo Marks


  What possible harm could there be in showing him the file? What use could C make of it?

  But I knew that I wouldn’t, and heard myself telling him that the best person to address his questions to was Nick.

  He looked at me with such understanding that I knocked the thing I most believed in on to the floor.

  He picked up the WOK and smiled. ‘Excellent,’ he said.

  I was barely able to listen as he delivered his formal verdict on WOKs, which he referred to by their proper title, worked-out keys. As far as I could gather I’d made an important contribution to agents’ coding … But none at all to Kergolay, Plan Giskes, or any of the other matters I should have discussed with him.

  He listed the WOK’s assets, which far outweighed my own. It had the great merit of being a one-time code which agents could destroy message by message and could not possibly remember. It saved them the wearisome business of numbering transposition keys, and would virtually end indecipherables as the indicators were proof against Morse mutilation. The number of letters passed in a WOK could safely be reduced to a hundred and its security checks were high-grade. However, he had two reservations, though they were not about the system itself. He had my full attention now.

  He doubted whether shuffling counters by hand would produce transposition keys which were truly random, as the girls would inevitably grow bored or careless. It would be far safer if Bletchley produced the keys by machine and he would ask Commander Dudley-Smith, one of his principal assistants, to contact me to discuss the quantity of keys required.

  His more important reservation concerned the destruction of the keys as soon as they’d been used. How would an agent do this in field conditions? He regretted that he had no suggestions to offer. I told him that I’d ask our research station to produce a specially sensitised silk which would make the keys easy to cut away and burn. I caught him looking at me with a specially sensitised face – a one-time expression which he quickly put away before his traffic could be read. But I had no difficulty in interpreting the tummy rumbles (his) which suddenly filled the office, and realised that it was well past lunchtime.

  He did as much justice to Mother’s provisions as any three coders, and chatted about a visit he’d once made to 84. But over his last cream bun he said that there was something he’d been meaning to ask me.

  I hadn’t relaxed over lunch and was ready for anything – absolutely anything. Except for his question.

  He wanted to know how I’d managed to avoid being sent to Bletchley.

  I told him that I’d had no need to avoid it because the question had never arisen. Bedford had done everything possible to help me but I was a hopeless pupil and was glad to accept the first job offered. He said that if ever I wrote a paper about unteachable pupils he’d like to read it. And perhaps I’d be interested in visiting Bletchley? He had no need to ask twice and told me to arrange it with his secretary. And when I did come, perhaps I’d bring the last lines of the charts with me?

  He glanced at his watch and said he must go. He held out his hand and repeated his invitation to visit Bletchley, though he couldn’t provide me with this kind of lunch.

  I wanted to thank him for the banquet which he’d given me, but a question popped out before I could even begin. ‘Colonel Tiltman, sir, is there any reason why agents shouldn’t use one-time pads?’

  Colonel Tiltman sir didn’t so much change colour as rank and I caught a glimpse of Lieutenant Tiltman as he must have looked to Lieutenant Nick. ‘One-time pads, did you say? For agents?’

  He quickly resumed his rank, which was peerless. ‘You can discuss it with Commander Dudley-Smith when he comes here. Please thank your secretary for the tea.’ He hurried away as rapidly as Nick had.

  What was wrong with giving agents one-time pads?

  Depression set in the moment he left, and I was alone again with my own flashy talent.

  Although he’d praised WOKs, I’d lacked the courage to disobey orders and discuss the Dutch traffic with him. He’d know better than anyone if Plan Giskes would work.

  I felt like a rat who’d produced an antitoxin. It was the kind of loneliness that made schooldays seem companionable.

  There was only one thing I could do about it, though I never thought I’d need to. I asked to be put through to the Signals Office with top priority, and told the menaces that it was time to come home.

  Notes

  * The letters ING were the start of Skinnarland’s next line.

  * He transmitted it in December ’41 and when I joined SOE in June ’42 I broke it as a matter of interest.

  TWENTY-ONE

  Repercussions

  A stickler for established procedure, especially when it was he who’d established it, Sir Charles Hambro never communicated with the lower orders except through the heads of their directorates. But the morning after Tiltman’s visit he sent a personal message ‘from CD to the coders of Grendon’ congratulating them on breaking over nine hundred indecipherables, urging them to maintain their great efforts and assuring them that a new code called Works (sic) would make their task much easier. He also undertook to visit the station shortly to congratulate them in person.

  The testimonial remained on the Grendon noticeboard until an anonymous FANY spelled out in capital letters the four-letter word which she believed the C of CD stood for.

  It was typical of Tiltman to have put in a word for the low levels when dealing with the highest, and although Nick wouldn’t disclose what else he’d told CD after he’d left me, its repercussions were immediate. I was transformed overnight from WOK-pedlar into licensed code-maker, with authority to recruit six WOK-makers, six WOK-briefers, and the staff of the Thatched Barn to do the camouflage. I also had authority to launch Plan Giskes.

  My licence to be a trap-setter hadn’t come from SOE but from an authority with wider terms of reference: my own free mind. Now that Tiltman was SOE’s adviser, I need no longer worry about the future of agents’ codes if Plan Giskes cost me my job.

  But I was beginning to run out of excuses for visiting the Signals Office in case the Dutch section cancelled a message to the field and I wasn’t on hand to make improper use of it.

  *

  To briefing officers, every agent was a problem. But Francis Cammaerts was a problem agent. Officially I knew nothing about him. Nothing, that is, except for the few mandatory details every country section supplied with a ‘body for briefing’.

  He was a Buckmaster agent, would be known in the field as Roger, and was due to go into France in the March moon. Further information would be irrelevant to the teaching of double-transposition. If it hadn’t been for the grapevine operated by the Brotherhood of Briefing Officers I would never have known about Francis Cammaerts’s extraordinary past, which set him apart from any agent in our combined experience.

  None of us quite understood what he was doing in SOE. He was an ardent pacifist, who refused to join the armed forces as all human life was sacrosanct and it was wrong to take it under any circumstances. He registered as a conscientious objector and was summoned to appear before the tribunal set up to judge the sincerity of ‘conchies’. After cross-examining him about his principles, the tribunal ordered him to take up agricultural work for the duration of the war. After a year as a farm labourer he volunteered to be dropped behind enemy lines. Some thought it was the death of his brother in the RAF which had convulsed his thinking, others that he was sickened by what he’d read about Nazi atrocities. Whatever the truth of it, he’d convinced Selwyn Jepson, SOE’s chief headhunter, and Maurice Buckmaster, a tribunal of one, that he was an excellent prospect as both saboteur and organiser, and they’d recruited him into SOE.

  The Brotherhood of Briefing Officers (BOBO for short) unanimously disagreed with his acceptance. Although they reluctantly conceded that he was highly intelligent, in the opinion of the BOBO he had no flair for sabotage or leadership and was in conflict about reversing his attitudes. The kindest comments about him came (as they
so often did) from his coding instructor at Beaulieu, who said in his report that he was ‘a plodder who does his best to follow instructions but seems unable to grasp the basic principles’. A schoolmaster by profession, and apparently a gifted one, he’d proved a problem pupil on every course he’d so far attended.

  Reluctant to leave my desk in case N section cancelled a message to the field, I resolved to spend as little time briefing Cammaerts as I conscientiously could. There would be ample time between now and March to rebrief him if I made the plodding progress I anticipated.

  I was quite unprepared for his physical impact. Buckmaster had cornered the market in giant agents, and this one dwarfed even Rabinovitch, whose Orchard Court chair he was straddling with equal discomfort.

  There was nothing plodding about his eyes as they assessed the merits of his briefing officer. Nothing plodding about the way he wrote out the text of the message he was about to encode. It was when he started to encode it that he began living up to his reputation.

  He paused after every five letters as if counting heads in a classroom. Eventually satisfied that all were present and correct, he appeared to form the letters into a crocodile, which he led in slow procession across the courtyard of his paper. There was another pause while he took a roll call. And yet another while he seemed to rebuke some letters he’d caught pulling faces at each other. And that was only the first transposition.

  By the time he’d reached the second I could have strolled to the nearest church, said a prayer for Tiltman’s preservation and waited for an official acknowledgement. Instead I glanced at his code card.

  His poem was in French, and I remembered that his uncle was a famous Belgian poet. If he’d chosen one of his, I hoped he’d do justice to it.

  The BOBO’s explanation that Cammaerts was a plodder wouldn’t help me to unplod him. Yet the longer I watched him at work, the more I began to suspect that he wasn’t plodding at all. I asked him to stop encoding for a moment. I was going to take a gamble with Cammaerts which might bring him to a permanent standstill.

  I showed him the mathematics of double-transposition.

  If I’d been teaching him to drive (which God forbid, for both our sakes) I’d have assessed him as someone who needed to understand the mechanics of his car, because he suspected that it wasn’t roadworthy and that he’d have to be his own breakdown service on this particular journey.

  Feeling like a spiritual AA, I did my best not to talk down to him. Sensing that maths wasn’t his subject (it turned out to be history), I explained as simply as I could what happened to the letters as they were shuffled through their ‘cages’, and showed him the relationship between the code groups when the transposition was complete. His questions showed that he’d understood every word of it, and I didn’t lose him at all until I forgot that I wasn’t trying to turn him into a cryptographer.

  As if to confirm that he’d seen enough, the man with a need to know resumed his encoding. He didn’t spurt or do anything spectacular but cruised towards the traffic lights, waited till they changed and proceeded quietly and steadily to pass his driving test.

  There was a lesson in all this. The more intelligent the agent, the less likely he was to respond if he were taught the mechanics of coding mechanically.

  I’d been slow to realise that what Cammaerts had really been doing was coding with character, testing the logic of it all, trying to satisfy himself that these alien procedures were soundly based, taking nothing and no one for granted, least of all his various instructors.

  It was going to need a special calibre of WOK-briefer to deal with agents like this one. I couldn’t recruit FANYs for their looks alone. I decided to be selfish and show him a WOK myself. There would be plenty of time between now and March to make sure that he understood the thinking behind it.

  I realised that he was asking me a question. He wanted to know if maths was my subject, and I told him that I didn’t have one.

  He looked hard at me and smiled.

  It may have been the quality of that smile or the penetration of that look, but I found myself feeling very sorry for anyone who made the mistake of writing this man off.

  Unless he happened to be German.

  On 15 February I had a better excuse than usual for visiting the Signals Office. The night squad had broken an indecipherable from Rabinovitch after fifteen hundred attempts, and I wanted to teleprint my congratulations.

  Bingham of the Dutch section slithered towards me and asked if we could have a quick word, though we rarely had any other kind. He was a verbal weight-watcher. He said that he wanted to cancel a message to Holland but didn’t know the new procedure. Who should he talk to?

  It took me a moment to realise what he’d said. He wanted to cancel a message to Holland. It was the first time I’d been tempted to kiss a fox.

  I told him that he was talking to the right person and that I’d be delighted to cancel it for him. He said that it was message number 60 to Boni and thanked me for my help as he had a meeting in five minutes. Lowering his lisp, he added that if it was too late to cancel the message, it wouldn’t really matter as he was sending a message to Boni tomorrow changing his instructions. He thanked me again and hurried off to keep his appointment.

  I hurried in to the supervisor to keep mine with Giskes.

  Number 60 to Boni was on top of a pile of messages waiting to be teleprinted to Grendon. I told the supervisor that there was a query on it which the country section wanted to discuss with me and that if she’d give me her copy I’d return it as soon as I could. She handed it over at once.

  An empty office. A cancelled message. A panic attack.

  The entire concept could be wrong.

  I picked up the receiver to speak to Tiltman. It put itself back.

  I wished I knew what moral courage was, but it was too late to ask Cammaerts to define it, though those who have it seldom can. I remembered his smile, picked up my pen and with an unsteady hand prepared the cancelled message for transmission to the field.

  Plan Giskes had begun.

  TWENTY-TWO

  The Launching of Plan Giskes

  Locked in my desk in readiness for this moment were brief notes on the background and performance of every Dutch agent, and a detailed blueprint of Plan Giskes.

  At arm’s length with the plan at last, I reviewed the elements likeliest to determine its outcome:

  1 Boni’s record (no detail could be considered irrelevant)

  2 The message to be sent to him

  3 The concept itself.

  Boni’s Record

  Boni (formerly known as Spinach; real name Cornelis Buizer) was dropped near Assen on 23 June 1942 with his organiser Parsnip. He had been transmitting regularly ever since and had become one of the busiest operators in Holland, handling not only Parsnip’s traffic but that of Potato and other key members of the Parsnip–Cabbage organisation.

  A radio operator in peacetime, his ‘touch’ at the keyboard and knowledge of wireless procedures made him, in the words of a Grendon signalmaster, ‘as good if not better than anyone here’. His coding was equally efficient and his security checks were invariably correct, though he had twice omitted them.

  The volume of traffic which other agents entrusted to him allowed him to straddle most of the bizarre events which had taken place in Holland in the past six months.

  It was Boni who had been at the heart of the traffic snarl-up between London and Holland which lasted from 3 August to 12 November last year.

  It was Boni who suggested that all Parsnip’s traffic should be in his (Boni’s) code. He subsequently made the same suggestion for all Potato’s traffic. N section acceded to both requests, Ozanne refusing to intervene.

  It was Boni who claimed that two key messages from London to Potato had been indecipherable. These messages had been checked and rechecked and had been perfectly encoded. Nor had there been any atmospheric problems which might have caused Morse mutilation to the indicator groups. It was far
likelier that the Germans had been unable to answer London’s questions satisfactorily and had been playing for time.

  The Cancelled Message

  Message number 60 to Boni of 15 February was in reply to his number 58 of the 9th, in which he’d confirmed that a reception committee would be standing by for Broadbean and Golf. He’d also stated that he would run completely out of funds within the next two months and asked London to send money urgently. He’d added that he was recruiting new agents for the Parsnip–Cabbage organisation.

  The message which Bingham wanted to cancel promised Boni that 10,000 florins would be despatched with Broadbean and Golf, and confirmed that the reception committee should stand by for a dropping operation on the 16th. It also confirmed the arrangement of the lights and asked for details of the new recruits he was enlisting. It ended with a sentence in Dutch which I took to be a message to be broadcast over Radio Oranje or a password to be used in the field.

  This was an excellent message for the purpose of Plan Giskes. It was long (over three hundred letters), had substance and, above all, called for a reply. The nature of that reply would determine whether Boni and the agents for whom he operated were in enemy hands.

  The trap was basically so simple that its best chance of success lay in the Germans not believing that it could have been devised by simpletons.

  The Concept

  I intended to send Boni an indecipherable message which he could not possibly decode without the help of a cryptographer.

  But it would be no ordinary indecipherable. These can sometimes be broken by luck. This indecipherable would be encoded in such a way that if Boni replied to it other than by stating that it was indecipherable, then an expert must have helped him to unscramble it. And that expert had to be German.

 

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