Alphabetical (10 page)

This square is known as a ‘Vigenère Square', named after a French ‘diplomat' Blaise de Vigenère (1523–96). In 1586, he wrote
Traicté des Chiffres, ou Secrètes Manières d'Escrire
(
Treatise on Ciphers or Secret Ways of Writing
). He had been studying the works of previous cryptologists: the Florentine painter, composer, poet, philosopher, zoologist and architect Leon Battista Alberti; a German abbot – Johannes Trithemius; and an Italian scientist – Giovanni Porta. According to Simon Singh, accomplished author of
The Code Book
, the breakthrough in creating these kinds of multiple-letter codes came in around 1460, when Alberti was having a stroll in the gardens of the Vatican with his friend Leonardo Dato. He went on to write a treatise in 1462 on ciphers called
De Cifris
where he revealed the wonders of the Alberti Cipher Disk. A version of Alberti's disc was used by the Confederates during the American Civil War.

If you're ingenious, you could make a version of this. Make two discs out of cardboard, one bigger than the other. For the sake of precision, mark each one of them with lines radiating
out from the centre, like bicycle-wheel spokes. Make twenty-six segments, so you have spaces for twenty-six letters. Write each of these in turn at the outermost point in each segment and on each disc. Now place the larger disc underneath the smaller disc. You could stick a split pin through the middle to make rotation of this inner disc easier. In one position, all the letters on both discs match exactly, ‘A' for ‘A', ‘B' for ‘B', and so on. If you rotate the inner disc by one segment, you will make N + 1. If you rotate the inner disc by three segments, you will make Caesar's ‘code', N + 3. These formulae are known as ‘keys'.

Cunning old Alberti, who also wrote a treatise on the cunning old housefly, worked like this: before writing to you I will tell you a letter. You own a cipher disc. Before starting to read the ciphered message you must set your discs to the letter I've told you. Alberti set his inner disc with the ‘K' on the inner disc matched to the outer ‘B'. ‘If you want to read my message,' said Alberti, ‘you must use the identical formula you have with you, turning the inner movable disc until the letter B corresponds to the index k.' What Alberti called an ‘index' we might call the ‘key letter'. The inner disc provides the letters for the cipher message, the outer for the ‘real' or ‘plain' message. He also suggested ways in which you could hide key letters in a message. Very cunning, Alberti.

Of course, with your discs, you can write whatever you want and in any order on the two discs. Provided the people receiving your message have the same letters and signs on their discs, and they know what are the signals to move the inner disc round, you can make your ciphers yet more undecipherable to the uninitiated. However, if you want to behave as we've all done in relation to the internet, you will write a series of messages to people which you think are secret and confidential and then hand your discs and keys to the security services of another
country. You will then be surprised that they now know what it is you've been writing.

Between 1938 and 1949, there was an Ovaltine-sponsored radio show in the US called
Captain Midnight
which would end with a secret message. Listeners wrote to Ovaltine for their ‘Code-O-Graph' which would enable them to figure it out. In the storyline they were used by agents of the Secret Squadron, a paramilitary organization headed by Captain Midnight. On the outer disc of the ‘Code-O-Graph' were letters, on the inner disc numbers. Captain Midnight gave you his secret message and you used your ‘Code-O-Graph' to decipher it.

The first Code-O-Graph, called the ‘Mystery Dial' unit, was introduced in 1941, as a device to enable Secret Squadron agents in the field to send and receive secure messages. It was in badge form. The front of the badge displayed the number and cipher alphabet scales. The reverse had two windows, one labelled ‘Master Code'; the other, ‘Super Code'. As an example, if the cipher was designated as ‘Master Code 3', it meant that the movable rotor was spun so that the number 3 would appear in the window labelled ‘Master Code'. This setting would align the number and cipher alphabet scales correctly to decipher a message.

The 1945 model altered the cipher-key setting scheme. The new method was to align one of the letters on the alphabet scale to a numeral on the number scale. For instance, the ‘Master Code X-15' setting meant that the letter X would be moved until it was next to the number 15 on the number scale. The 1946 model was the ‘Mirro-Flash' unit; the 1947 was called the ‘Whistle Code-O-Graph'; the last Code-O-Graph was the ‘Key-O-Matic' unit. Resetting the cipher elements utilized a small key that was inserted into slots over one of the gears, which could be disengaged, using the key and a leaf spring as a clutch.

From Alberti to
Captain Midnight
in 500 years.

An earlier hero of the cipher world was Arthur Scherbius (1878–1929), a German electrical engineer who was born in Frankfurt am Main; his father was a small-businessman. He studied electricity at the Technical College in Munich, and his doctoral dissertation was called ‘Proposal for the Construction of an Indirect Water Turbine Governor'. He was a bright chap. In 1918, he founded the firm of Scherbius & Ritter, inventing a number of things, including electric pillows and ceramic heating parts, and in 1918 he patented a machine, initially pitched at the commercial market, which he later sold as the Enigma.

I am not going to pretend to be an expert on Enigma, and unlike Mick Jagger, I don't own one. However, I think we can get a general idea of how the Enigma machines mangle the alphabet if we were to imagine a series of Alberti's cipher discs lined up next to each other. Then by a series of ‘trips' whereby a whole 360-degree rotation of one disc can trip off an adjacent disc and along with electrical impulses, we can align and realign these discs in many different ways. Keys or Alberti's index letters can be used to set the machine to ‘scramble' letters into a cipher. Scherbius made it even more fiendish with the use of a ‘reflector' which entailed sending the scrambling back through the system to scramble it even more. There was also a yet more fiendish element called the ‘plugboard' which swapped round some letters from the real message before it even entered the scrambling-reflecting system! There were several commercial models, and one of them was adopted by the German Navy (in a modified version) in 1926. The German Army adopted the same machine (also in a modified version somewhat different from the Navy's) a few years later. Scherbius saw none of this as he was killed in a horse-carriage accident in 1929.

I guess the Enigma machine represents the industrialization of diplomacy and military intelligence. It is the outcome of mathematical knowledge in conjunction with technology applied to the humble old alphabet. Throughout history, the intellectual endeavour involved in all this ciphering has been mostly employed by governments, armies, and spies, as part of their role in gaining and maintaining power or in winning wars. I don't think I'm exaggerating when I say that the pages on which ciphers have been written are stained with blood – always morally justified at the time, of course.

My memory of ciphers from when I was a child, though, is that they are great fun. It's as if the ‘real' alphabet is transparent but when you use a cipher it becomes opaque. The truth is on the other side, if only you can get to it. If you're the one using the cipher, you are the owner of this occult knowledge, and it gives you – and those who know the trick – power over those who don't. It is an alphabetic way of whispering behind someone's back: they can hear or see that you're talking but can't make out what you're saying.

Ciphers reveal some important things about the alphabet. Making an alphabetic cipher (substituting one letter for another) drains the letter you are looking at from the purpose for which it was invented, which is to invite you to make a particular sound. The only things that matter in cipher-making, though, are the relationship between one letter and another in the ‘real' alphabet and then the relationship between the letters in the ‘real' alphabet and the alphabet being used to make the cipher. These relationships are mathematical – to do with sequences. In this sense, this reminds us that the alphabet I'm using now, when viewed as a sequence, is random, more random than counting from one to twenty-six, where the sequence of numbers corresponds to the principle of increasing a quantity by one at
a time. Nothing is added when you say the alphabet from ‘A' to ‘Z' and nothing is taken away when you say it ‘Z' to ‘A'. It's not even arranged according to any principle of how the letters are used when we speak or write.

There's a reminder here of what the alphabet does beyond the matter of representing sounds. In ‘A is for Alphabet' and ‘B is for Battledore', I've shown a rather limited and elemental view of the alphabet. When we embed the alphabet in its real and actual use, we can see that it is a necessary part of a chain which goes far further than ‘representing sounds'. So, apart from when simply writing out the alphabet or playing with the letters as objects in themselves, we do not use the letters randomly. In use when writing, we group them according to what we want them to do when making words (and, on occasions, exclamations and interjections, and, with onomatopoeia, an imitation of sounds we hear).

Moreover, we don't make words randomly either. We put words into sequences or ‘strings', governed by the grammars we invent. And we invent grammars in order to make sense. So while the alphabet is random, and while we say ‘letters represent sounds', in fact, the full picture is: ‘letters are there for us to make sense'.

To give an obvious example: the letters ‘d' and ‘e' exist side by side in the alphabet. No one knows why they do. Saying ‘side by side' is in its own way a bit of maths or geometry. In fact, all the letters are equidistant from the ones next to them. The ‘D' is like ‘E' in the way ‘A' is like ‘B' or the way ‘U' is like ‘V': they are side by side. As a result, one way in which letters in the alphabet relate is that they are related to each other by similar or different distances. So, we might say, ‘B' is like ‘L' because they are both five letters away from ‘G' (one forwards, one back, but the distance is the same). This kind of thing is
what Caesar, Alberti, Scherbius and the rest were able to see and use.

However, back with ‘D' and ‘E': when we use them in language, we call on them to do a job based on linguistic principles, not mathematical ones. We do this frequently in English when saying – and therefore writing – ‘I walked from the bus stop to the station.' This is the ‘-ed' ending we invented in order to indicate that something happened earlier or ‘in the past'. In that sense, no matter what sound or sounds they make, ‘E' and ‘D' help us position events in relation to where we are now. Letters in context are doing a job in helping us make sense. This way of making sense is through ‘morphology' – that is, the making and changing of words; and through ‘grammar' or ‘syntax' – that is, the stringing together of letters and words in meaningful chunks.

Clearly, not all use of letters is as directly linked to grammar as this. Some of the ways in which we use letters meaningfully are to make distinctions between things, feelings, ideas, sounds, processes and much more. So, ‘shut' is different from ‘cut' because ‘sh' and ‘c' are different. We signify or point out differences in meaning through differences in sound, many but not all of which we can then indicate in writing by using different letters. The reasons for choosing ‘sh' over ‘c' are not only or simply because they are made up of different letters. Our ulterior motive is in order to make a different kind of sense, and that will be governed by what we want to say and who we are saying it to. We could easily think of the different situations in which we might want to write, on the one hand, ‘He shut his mouth,' and on the other, ‘He cut his mouth.' It's those situations which will be the ultimate reason why we choose between using the letters ‘sh' or ‘c'.

As I've said, part of the fun of playing around with ciphers
is that it involves principles utterly different from these. Cryptographers invent ciphers and use the alphabet by draining it of its purpose. In so doing, they throw into perspective what the rest of us, including cryptographers' masters, use the alphabet for.

THE STORY OF

•
AROUND 800 BCE
, we find the Phoenicians drawing a rough triangle and calling it ‘dalet' meaning ‘door'. Given that doors to dwellings made of soft materials are often triangular, this seems to be derived from a pictogram. The early ancient Greeks drew it with a downstroke on the right, turned the triangle into a semicircle and called it ‘delta'. When they switched their writing to run from left to right in around 500
BCE
, they flipped the semicircle over. The Romans added serifs and produced the elegant thick-thin line.