Decoded (18 page)

I have lost my freedom. If I wish to recover it, I have to decrypt PURPLE . . . I am sure that after working on PURPLE all these years you can offer me a few pointers to guide me through the maze . . . I have no experience in this kind of work, I need advice; any advice would be useful . . . Dear Professor Liseiwicz, curse me if you like, spit at me, hit me, I feel like a Judas . . .

It was of course impossible to post a letter with this kind of content straight to Jan Liseiwicz. In the end it was decided to send it first to some of our comrades in X country, who would arrange for it to be privately delivered. Even though they could be quite sure that it would arrive safely; as to whether or not Liseiwicz would reply, the people at Unit 701 were far from feeling confident. After all, this Jinzhen – the false Jinzhen – really was a Judas; most professors would not pay the blindest bit of attention to a student like that. To put it another way, this false Jinzhen was nicely poised between being pitiful and being despicable. Getting someone like Liseiwicz to ignore the despicable features and concentrate on the pitiable ones was going to be quite as difficult as cracking PURPLE. Sending this letter really was just trying their luck; it tells you that the cryptography division at Unit 701 was so desperate at this point that they would try anything.

Well, the miracle happened and Liseiwicz wrote back! During the next six months, Liseiwicz repeatedly risked a traitor’s death to contact our comrades, giving ‘dear Jinzhen’ a mass of material about PURPLE and suggesting ways to proceed in decrypting it. As a result, headquarters decided to temporarily create a PURPLE decryption working group, providing the majority of the cryptographers themselves. They were told to crack this difficult nut as quickly as they could. No one had any idea that Rong Jinzhen would be ahead of them all! In actual fact, by this time Liseiwicz had been patiently writing to Jinzhen for the best part of a year, without Rong Jinzhen having received a single letter – he didn’t even know the first thing about what was going on. That means that these letters meant nothing to him – if they affected him at all, it was by lifting the pressure a little bit. After all, when the directors realized that Jinzhen wasn’t working hard at his ciphers (in fact if anything he was even worse than before) they could easily have got rid of him as a complete waste of space – but the fact is that the Party decided to leave him alone. They did not need his input. He was going to be the bait that would allow them to decrypt PURPLE.

When people said that he was even worse than before, they were complaining about the fact that he was wasting more and more of his time in playing chess and reading novels; later on he also got into trouble for interpreting people’s dreams. Once they realized that he could interpret dreams, he attracted a horde of curious people, tracking him down so that they could tell him about the weird things that had popped into their heads overnight and wanting to know what it all meant. As with playing chess, Rong Jinzhen really didn’t know very much about the subject, but he found it difficult to say no to people’s faces. Maybe it is simply that he did not have the savoir faire to be able to turn them down politely. Anyway, he had no choice but to agree. He would take their tangled night-time thoughts and straighten them out into something that seemed to make good sense.

Every Thursday afternoon there was a political meeting for all the people working at Unit 701. They did different things at this meeting: sometimes a new policy would be explained, sometimes there would be a reading from the newspapers, sometimes there would be free discussion. When it was the latter, people would often drag Rong Jinzhen off into a corner and get him to interpret their dreams. There was one time where just as he was in the middle of explaining someone’s dream, he happened to come to the attention of the deputy division chief (one of the cadres in charge of raising political awareness) who was overseeing this particular meeting. This deputy division chief was very left-wing, and liked making a mountain out of a molehill – he was the sort of person that always leaps to the very worst conclusions. He decided that what Rong Jinzhen was doing was feudal superstition. Jinzhen was criticized in pretty severe terms and told to write a self-criticism.

The deputy division chief did not have many friends among his subordinates. The people in the cryptography division loathed him and so they all told Rong Jinzhen not to pay any attention to the man – just write a couple of lines and draw a line under the whole thing. Rong Jinzhen tried to follow this advice but his idea of how to draw a line under the whole thing and anyone else’s really did not coincide. When he handed in his self-criticism, it consisted of just one line: ‘All the secrets in the world are hidden in dreams and that includes ciphers.’

This is not the kind of thing that gets you out of trouble. He was clearly trying to prevaricate, as if interpreting other people’s dreams were in some way related to cryptography. There was even an arrogant overtone to the statement, suggesting that he was the only person who understood this crucial point. Even though the deputy division chief understood nothing about cryptography, he found the idea that something as individualistic as a dream could be allowed to go unchecked profoundly disgusting. He looked at the self-criticism and felt as though each word were pulling faces at him, sneering at him, humiliating him, running wild, throwing stones . . . how could this possibly be acceptable? He was not going to stand for this! Jumping up, he grabbed hold of the self-criticism and rushed furiously out of his office. Leaping onto the back of a motorbike, he drove straight for the mountain cave. He kicked open the steel door to the cryptography division and right there in front of everyone he swore at Rong Jinzhen, using the tone of voice of a much-tried superior. Pointing at Jinzhen, he fired off his final shot: ‘You have expressed your opinion; now let me tell you mine: every ugly toad thinks that sooner or later he is going to get to eat the meat of a swan!’

The deputy division chief had no idea that he would have to pay a horrible price for what he said on this occasion; in fact, he ended up being so humiliated over it that he had to leave Unit 701. The fact is that while the deputy division chief was maybe a little hasty, it was the kind of thing that everyone in the cryptography unit was also saying – they found nothing wrong with it at the time; in fact, as far as they could see he had it absolutely right. As I have said before, in order to succeed in this solitary, difficult and dangerous profession, quite apart from great intelligence and the necessary knowledge and experience, you also need a luck that comes from far beyond the stars. The impression that Rong Jinzhen had given everybody was that he simply did not have the natural intelligence required. Furthermore, he had shown no signs of being either lucky or of creating his own luck. It seemed more than likely that the deputy section chief was right.

There is a proverb in China which these people should have remembered: ‘You cannot measure the ocean with a ladle; you cannot tell what someone can do just by looking at him.’

Of course, the ultimate reply to his detractors was that one year later Rong Jinzhen cracked PURPLE.

One year!

He decrypted PURPLE!

Who would have guessed that at a time when everyone was avoiding PURPLE like the plague, this so-called ugly toad was just squaring up to the task! If anyone had realized what he was up to, they would have laughed at him. Sometimes people say that the ignorant are fearless. Well in this case, as it turned out, the facts demonstrated that this particular ugly toad was not only a genius, he also had the luck of one. He had the luck that comes from far beyond the stars. He had the luck that you see when you raise your hands at exactly the same moment as smoke appears above your ancestors’ graves.

Rong Jinzhen’s luck was unbelievable. You cannot ask for that kind of thing. Some people said that he decrypted PURPLE in his sleep – or perhaps it was as a result of interpreting someone else’s dream. Some people said that he found inspiration in the chess games that he played with the lunatic. Some people said that he got the key to the whole thing when reading one of his novels. Whatever the truth of the matter, it seemed as though he had managed to decrypt PURPLE with hardly any effort – that really amazed people, as well as making them jealous and excited! Everyone was excited. Jealousy was left to the experts who had been sent by headquarters. They really thought that with the pointers Liseiwicz was sending them, they would be the ones who would be lucky enough to decrypt PURPLE.

This was the winter of 1957. Rong Jinzhen had spent just over a year at Unit 701.

Twenty-five years later, the crippled director of Unit 701 sat in the middle of his very plainly appointed living room and told me that when everyone else was using a ladle to measure the potential of Rong Jinzhen’s sea, he was one of the few people who still held out any hope that he might ever achieve something. To hear him tell it, no one else at that time really understood Jinzhen in the slightest. I don’t know whether this is all hindsight, or whether the thing really did happen the way that he said. All I can tell you is what he told me:

[Transcript of the interview with Director Zheng]

To tell the truth, I have spent my entire life working in cryptography and I have never seen anyone with such a remarkable sixth sense where ciphers were concerned as [Rong Jinzhen] had. He seemed to find a kind of connection with the ciphers he worked on, an umbilical connection such as you see between a mother and baby – whereby a great deal of information seemed to pass directly between them, through the blood as it were. That was one impressive thing about the way he approached a cipher. The other impressive thing was his remarkable powers of concentration and his cold and calm intelligence – the more other people gave the thing up as hopeless, the more determined he was to push it. He really didn’t care what other people thought about him. His creative abilities were fully the equal of his intelligence – they were a key part of his personality. In both cases they were easily double that of an ordinary person. When you discovered just how magnificent his quiet achievements were, it was inspirational; but also made you realize how puny and incapable you were in comparison.

I remember particularly, not long after he had joined the cryptography division I went to Y country to participate in a three-month professional assignment – it was also to do with PURPLE. At that time Y country was also working on decrypting PURPLE and they had got a lot further with it than we had – headquarters decided to send us there specially to see what we could learn. Three people were selected to go, me and one of the cryptographers from my section, plus a deputy division chief from headquarters – the man who oversaw our work on behalf of the central authorities.

When I got back I heard a lot of complaints about Jinzhen from the directors of our division and my co-workers; they said that he wasn’t concentrating on his work, that he wasn’t really getting into the spirit of the thing, that he didn’t make demands of himself, and so on. I was very upset to hear this, of course, because it was I who had brought him here – I was supposed to be bringing back an expert and apparently all I had managed to recruit was a clown. The following evening I went to his rooms to find him. The door was ajar. I knocked and there was no answer, so I went in. There was no one in the main room, so I went through to the bedroom. I could see that he was curled up on the bed fast asleep. I coughed and walked into the bedroom, switching on the light. When it clicked on, I was amazed to discover that the walls were plastered with diagrams. Some were like logarithmic tables, covered with lines twisting and turning across each sheet of paper; others were more like trigonometric tables, and their numbers, written in all the colours of the rainbow, seemed to quiver like soap bubbles caught in a beam of light. The whole room seemed as magical as a castle in the air.

When I looked at the annotations he had made to each of the diagrams, I immediately understood that he had rewritten the
History of Cryptography
in a more concise form – if it hadn’t been for those notes, I simply wouldn’t have understood what it was all about. The
History of Cryptography
was this massive fat book – three million Chinese characters – and he had managed to condense it down to these simple annotations using just a few lines of numbers – that really did impress me very much. To be able to look at a body and see the bones beneath the skin, to represent them exactly upon paper – that is the work of a genius. But he didn’t even need the skeleton – he had just taken a single finger bone away! Just think about it: think what it means to be able to recreate the whole living organism if all you have is one finger bone!

The fact is that Rong Jinzhen was a genius – there were many things about him that an ordinary person simply could not understand. He could go for months, maybe as long as a year, without saying a word to anyone – it really didn’t seem to bother him – but when he did finally open his mouth, he would say something that quite possibly was more important than everything you have said in your entire life put together. Whatever he did, it seemed as though he did not care about the process at all, the only thing that mattered was the result. The results of what he did were always perfect – it was amazing! He seemed to have an uncanny ability to get to the crux of the matter, but the way that he went about it was unique, peculiar; something that you would never have thought of in a million years. To put the
History of Cryptography
up in his own room – who would have thought it? Nobody else behaved like that. Let me make a comparison. If we say that a cipher is like a mountain and that decrypting that cipher is like finding the secret hidden in the mountain, then the first thing that most people would do would be to find a way to climb the mountain and when they got to the top, they would start looking for the secret. He wouldn’t do anything of the kind. He would go and climb a completely different mountain and then when he got to the top, he would fire up a searchlight and start looking for that mountain’s secret using a telescope. He was a very strange person, with truly remarkable gifts.

There can be no doubt that when he decided to move the
History of Cryptography
into his room in this strange way, he was ensuring that his every move, waking and sleeping, was in some way linked with decryption – you can imagine that each cipher recorded in that book seemed to be breathed into his lungs like oxygen, passing through his blood until it reached his very heart . . .

. . . The first shock I got was from what I saw. However, I immediately received a second shock from what he said to me.

I asked him why he was wasting his time with history. In my opinion, cryptographers are not historians; for a cryptographer to get involved in the history of the subject is stupidly dangerous. Do you know what he said?

He said, ‘I think all ciphers are like living organisms – because they are alive, there is an invisible connection between the ciphers in use in history and those that we use today; furthermore, all the ciphers developed at the same period in time have an intimate relationship. Whatever the cipher is that we want to decrypt now, the answer may well be hidden in an earlier one.’

‘When people create ciphers,’ I said, ‘they have to eliminate every sign of their history; otherwise when you cracked one message you’d crack them all.’

‘That doesn’t affect my basic contention,’ he said. ‘If you are trying to eliminate history from all your ciphers, that also creates a connection between them.’

That really did open my eyes!

He continued, ‘Changing a cipher can be compared to changing a face – it is shaped by trends in evolution. The difference is that the changes of a human face are always predicated upon the same basis – no matter what you do it is still a face, though you may have changed it to make it even more face-like, even more perfect. The changes that you can introduce to a cipher are completely different – today it is a human face, but tomorrow you can make it change into something else – a horse’s face or a dog’s face, or maybe the face of something else entirely. It has no fixed parameters. But no matter how much you change it, the internal features are simply refined, clarified, advanced, rendered even more perfect – that is an evolutionary development that you cannot escape. It is a given that every effort is made to change the face, but it is also a given that you try and make the internal structure more refined – these two givens create a twin path that goes right to the heart of any new cipher. If you can find those two paths in the forest that is the history of cryptography, then they will help you in decryption.’

While he was explaining this, he was pointing to the columns of figures written up around the room like a hoard of ants. Sometimes his finger moved, sometimes it was still, as if he were gradually working his way through to the very heart of the matter.

To tell you the truth, I was astounded by his idea of the twin paths. I understood immediately that although in principle these two paths had to exist, in actual fact they might well not exist at all. Maybe nobody else realized, but if you treated those paths as strings and pulled on them, the person tugging would in the end find himself garrotted . . .

Of course I will explain what I mean. Tell me, what does it feel like when you walk closer and closer to a bonfire?

Exactly. You will feel a hot, burning sensation. After that, you do not dare to get too close; you want to preserve a certain distance, so that you won’t get burned again. The same principles apply when you get close to a person – the influence that a particular person exerts over you depends on their individual attractiveness, character and capacities. I can tell you categorically, regardless of whether you are talking about a person who creates ciphers or a person who decrypts them, cryptographers are the most remarkable people, with really unusual capacities – their minds are like black holes. Any one of them is capable of exerting an enormous influence upon their fellows. When you walk into the forest that is a cipher, it is like walking through a jungle in which there are countless traps – at every step you run the risk of falling into one and not being able to get out again. That is why those who create ciphers ( just like those who unlock them) don’t dare think too much about the history of encryption, because each concept, each theory in the history of this field can attract you like a magnet; can destroy you. The minute your attention has been distracted by one of these concepts, you are worthless as a cryptographer, because ciphers cannot have any intrinsic similarity to one another, to prevent them from being cracked too easily. Any similarity would make the two ciphers so much rubbish – ciphers are indeed heartless, mysterious things.

Well, now you can see why I was so amazed – the two paths theory that Rong Jinzhen had developed resulted in him disobeying one of the cardinal rules in cryptography. I don’t know whether he was ignorant of it, or whether he knew and decided to go ahead anyway. Given the first shock that he had caused me, I think that it is most likely that he knew and had decided to go ahead regardless – he was intentionally breaking one of our cardinal rules. When he hung the diagrams he had worked out from the history of cryptography up on his walls, he was demonstrating that he was of no mean intelligence. He was breaking the rules not because he was stupid and ignorant, but because he knew exactly what he was doing and was brave enough to go ahead with it.

When I heard his two paths theory, I didn’t criticize him the way that maybe I ought to have – I was struck with a kind of silent admiration, not unmixed with jealousy, because he was clearly way ahead of the rest of us.

At that time, he had not even spent six months in the cryptography unit.

I was very worried about him, because it seemed to me that he was in a very perilous situation. As you will now realize, Rong Jinzhen wanted to tug on the two strings that he had found – that meant that he was proposing to become entrenched behind every concept and theory in the history of cryptography, cutting his way through each of the countless layers of evolution to reach to the underlying principles. Every single layer would represent endlessly attractive theories and concepts, any one of which might lay its dead hand upon his mind and turn everything that he had done into worthless rubbish. That is why for so many years there had been one unwritten rule in cryptography: Avoid history! Everyone was perfectly well aware of the fact that there – in the history of the subject – there was no doubt any number of opportunities and pointers to help decrypt modern ciphers. But the fear of going in and not being able to find a way out overcame all other considerations – that was more important than any information to be found therein.

If I may put it in these terms, the forest that is the history of cryptography is very silent and very lonely. There are no people there to ask the way from; nobody would dare to ask for directions! This is one of the tragedies of cryptography – they have lost the mirror of history, they have lost the sense of community that comes from planting the same seeds and harvesting the same fruit. Their work is that difficult and mysterious; their souls are that lonely and alienated – they cannot even climb on the bodies of those who went on ahead. At every stage they are faced with closed doors, with mantraps, forcing them to travel by side roads, to avoid any open path. For history to have become a troublesome burden to later generations . . . what an unhappy state of affairs! That is the reason why so many geniuses have been buried within the borders of cryptography – the number is appallingly high! . . .

. . . Okay, let me explain this in simple terms. The usual way that cryptography proceeds is by a slow process of elimination: the first thing that happens is that intelligence agents collect a load of relevant information and you then try and use this information to develop hypotheses – this feels very much like using a limitless number of keys to open a limitless number of doors. You have to design and make the keys and doors yourself – how endless the task is in practice is determined by how much material you have to work with; it is also determined by how sensitive you are to the cipher you are working with. I should explain that this is a very simple and stupid way of proceeding, but it is also the safest, the most secure, and the most effective. This is particularly the case when you are trying to decrypt a high-level cipher. Given the comparatively high success rate, this method is still in use today.

But Rong Jinzhen, as you understand, was not interested in doing it the traditional way. He had gone rushing straight into forbidden territory – in spite of the fact that he was a cryptographer he was immersing himself in the history of the field, standing on the shoulders of the giants of previous generations, and the only result to be expected from this was a terrible, frightening one. Of course if it worked, if he was able to come and go through every trap set by cryptographers of old, that would be a genuinely unbelievably impressive achievement. At the very least he would be able to narrow the focus of his search. Say for example that if there were 10,000 little byroads, he might be able to eliminate one half by this process – maybe less. The number that he would be able to eliminate would determine the prospect of success for his approach. That would decide how feasible it would be to put his two path theory into practice. To tell the truth, the success rate for such a thing was so low that very few people tried it and the ones that had succeeded were as rare as morning stars. In the world of cryptography, there would only be two types of people prepared to run so great a risk. One would be a genius, a real genius, and the other would be a lunatic. A lunatic is afraid of nothing, because he does not understand that the thing is genuinely frightening. A genius is afraid of nothing, because he knows he is armed with unusual weapons. Once he has made up his mind to the task, any difficult or dangerous obstacle can be overcome.