China Boat

Dear Jack:

Well, old man, it's Wednesday night, my time — Thursday morning, your time, as I write this — and we're finally getting somewhere, on this voyage of ours. Tomorrow morning we put in to Honolulu, our first stop on the way to Shanghai.

It seems as if this voyage has already lasted forever. You know why.

 … Tomorrow morning, we put in to Honolulu, our first stop on the way to Shanghai.

And that means, I'll finally get to mail you these letters I've been writing! And, we'll get to see if and how well Airmail really works, from overseas; I'm putting my letters to you in two different envelopes, just to keep them in manageable sizes; and also, to keep from putting all of my eggs in one basket, so to speak.

I suppose it's silly to worry about such things; and they'll all go on the same plane, anyway; it just seems like a long way to fly, over empty ocean, and then mountains and deserts. (And I can already feel you laughing at me, for my ground-hugger's ignorance of the reliability of modern aviation! All right, all right, I give in.)

Speaking of modern aviation — and that's a hint, by the way — yes, I'm sending you photos, after all! As you can see. The ship's lab came through for us, wonderfully. I'm actually sending you the best of the lot; although I'm ashamed to admit that they are the best. I'll just have to keep practicing, and trying harder.

I've written down dates and places and little comments, on the backs of the prints; just in case you're interested. Most are of San Francisco, and they go with my letters from there. But I've also included some shots of our boat, and my stateroom, and the decks and public spaces I've already described, in my later letters.

I deeply, deeply wish you were along for the trip, old man; I'm sorry we couldn't pull it off. But sharing these pictures of San Francisco and the boat with you, is a consolation; it means a very great deal, to me. And just knowing that you'll be seeing them, in just a few days — Well. It feels like a miracle. The best kind of miracle.

As it turns out, we're not stopping in Honolulu for very long; we get in, in the mid-morning, and we sail again around sunset; we're just dropping off, and picking up, passengers, and some more cargo. Still, it's a few hours, so my young shipmate Tom and I will be exploring, as best we can. (The old Hawaii hands have warned us not to expect too much; apparently, there isn't much tropical paradise to be found downtown. It's reserved for Waikiki, they say, and nice hotels like the Ala Moana and the Royal Hawaiian. Well, we'll see; and so will you, when you get the photos.)

In any case, we'll be on a mission. The President Hoover has a very nice-looking swimming pool; and Yours Truly needs a bathing-suit. (Don't laugh!) My own is packed away deep in the hold, and the only ones in the ship's onboard store are about three sizes too big … the same old story, for the both of us, I know. I suppose I could cinch a pair around my waist, with string or safety pins, or something, and wear them like pantaloons; I think, in the water, I'd look as though I were being eaten alive, by a jellyfish.

Neckties and bathing-suits; two of mankind's most useless and uncomfortable inventions. Bah.

Actually, a new bathing-suit for me, isn't our only mission; we'll also be shopping for Tom. Do you remember, I persuaded him to come running with me, on the top deck?

Well; as it turns out, it's more like I'm teaching him about running; starting with how to stretch. At his school, they just send the students off to run without stretching, without preparation of any kind; and no stretching afterwards, either, it's just start-and-stop. Can you imagine?

Anyway; his shoes are woefully inappropriate for the task, they're great, hulking clod-hopper things; so of course, he's developed blisters on the backs of his heels. So, we ran barefoot, yesterday; which made me footsore, along with him.

The upshot is, he's persuaded his parents to let him buy some decent running-shoes; if we can find any. I hope we can; I don't relish running barefoot all the way across the Pacific; teak decks are not the same as grassy fields.

It's actually an interesting friendship we've developed, he and I; and in so many ways and at any number of moments, I've wished you were here to share it, old man.

And especially, I've wished you were here to, well, advise me. Or better yet, to take the lead, the way you always have done, with the needier third-formers. I know, we're a team, and we work best as a team, I'll admit it; but you always know, better than I, what to say, what to do, straight off.

Well, in the meantime, I'm doing the best I can.

In any event — Tom and I are becoming good friends, as I've said. And within that friendship, there is just a touch of — protectiveness, on my part — ?

He is very young, and not terribly knowledgable; or perhaps not very worldly, would be a better way to phrase it; he is actually very, very smart, and very quick-witted. But he is not worldly, and he is going to live in a strange country, just as I did, once. Or twice, if you count my return to America; which I do.

As ridiculous as it sounds, I feel a little bit like an older brother, towards him. I will try to act the part, anyway; and not let him down … 

______

On a more mundane front — I've actually encoded my first business cable, for Father; and I have to tell you, J., it's a fascinating process.

Actually, I only did half of the encoding process; Father did the first step, behind looked doors — (!) — and he's told me nothing about his side of the process. In fact, he burned his plain-text document, in the ashtray in his cabin, before giving the results to me; those results were jumbled code-groups, and it was my task to encode them further. Or so I assume.

Father has surprised me, several times, on this trip. He has always been the soul of discretion, of course; he is a banker, after all. But I had never quite understood how much he keeps back, from me … it is somewhat worrying.

Anyway, old man; it is my part of the encoding process that I find so fascinating.

I am to use a cypher, called a Vigenère cypher, to further-encode Father's messages; and it is a cypher-method that is easy to use, for both the originator and the recipient; and it is 'almost' unbreakable.

'Almost' is, of course, the key word, here. According to Father's textbook, which describes the cypher-method, it can be broken by trial-and-error; if one has a very great deal of time, or a very great many people trying to break it, or both. And apparently, it can also be broken by sophisticated mathematical analysis; again, if one has a long enough message, and access to several skilled mathematicians, and, again, time. Father says that many governments, and even some businesses, have such resources, and routinely try to decode at least some important radiograms and cables; it is why he's using a two-step encoding process.

But failing such resources, it apparently is a virtually unbreakable cypher.

I was thinking, Jack — maybe we could try exchanging some cypher-messages, by mail, just as a lark — ? Perhaps you could even find a way to turn it into a school project, for extra credit? I think it might be wonderful fun!

So, old man; here is how the Vigenère cypher works.

First, one needs to construct the Vigenère square, the tabula recta. It's tedious; but one only need do it once, the same square can be used for all subsequent messages.

Start by printing out the letters of the alphabet, A through Z, near the top of a sheet of paper. (I suggest printing large, from experience; larger letters are easier on the eyes.)

Underneath that first row, print out the letters of the alphabet again; but this time, start with the letter 'B', and end with the letter 'A'.

Underneath that, print out another row; but this time, start with the letter 'C', and end the line with 'A' and 'B', following the 'Z' … 

You get the idea.

In the end, you'll have a square, with twenty-six rows, and twenty-six columns. The first row will read A through Z, left to right; the leftmost column will read A through Z, top to bottom.

The top row with be used with the key; the leftmost column will be for the plain text.

Here is how the key, and plain text, work.

First, on a separate sheet — a throwaway sheet; Father insisted I burn my working-page, after I encoded his message — write down the secret message, in plain text:

Next, one takes up the key; the key must be known to the sender and the recipient, (and no-one else!) Let's say, it's the first fragment of Lincoln's Gettysburg Address:

One prints the key, above the plain-text message:

As you can see, the key can be of any length. If it is shorter than the plain-text message, just start repeating it. One doesn't worry about punctuation or spaces; the final product will be grouped in five-letter bits, anyway, for ease of handling, and as an additional disguise.

Now comes the fun part.

Consult the tabula recta; go to the 'F' column, (the column underneath the 'F', in the first row); then, read down to the 'M' row, (the row which has the 'M' in the leftmost column); and find the character in which the row and column meet. In this case, it's the letter 'R'.

This is the first letter of the encrypted message.

Follow the same process for each letter in turn; and you'll come up with this, as the encrypted text:

Now, write out the encrypted text in five-letter groups:

Stand back, a moment, and look at it.

Rather impressive, don't you think, old man?

The decryption process is straightforward. One writes the key phrase in, above the encrypted text; one uses the top row of the Vigenère square, for the letters in the key; one looks down in each column, to find the letter in the encrypted text; and then, one looks to the leftmost column, this time, to find the corresponding, correct plain-text letter. It is just the reverse of the encryption process.

There are drawbacks, of course.

I'll be the first to admit, J., that the process is tedious; encoding Father's message took me almost an hour, and it wasn't a long one. Too, Father insisted I double-check my work, and I did find an error; which was humbling. And then, he double-checked it all himself, which was not flattering.

In any case, I found that using a ruler — or two — helps. In fact, tomorrow I'm going to draw in ruled lines, for the columns and rows of my tabula recta. That should help, a great deal more.

Still. The tedium is a small price to pay, for the privilege of privacy, don't you think, old man? Think how much fun it will be, sending 'secret' messages to one another!

______

And that, Jack, is about all the fun I can contemplate having, tonight. It's getting late.

I am very much looking forward to tomorrow; and not just for the sake of stretching my legs in Honolulu. Actually mailing these letters to you will be a profoundly satisfying experience. And if airmail-delivery has worked out, and I am lucky enough to have a line or two from you waiting for me, I will be very happy, indeed.

I also hope, very much, that all is well with you, your family, and our friends.

Take care of yourself, old man, all right? And, watch out for reports and photos from Your Man In Hawaii, coming soon! (Well, in a few more days, or weeks, really, anyway … a disturbing thought. I wish like anything that there was a post-office in the middle of the Pacific, closer than Yokohama. But you'll get the reports, and the photos, I promise!)

Take care, Jack.

Yours, always —

Rhys

M.O.C.