Children of the Fleet (Fleet School #1)(58)
Word searches were boring to Dabeet; he had outgrown them by age four. All they were was a series of treasure hunts with singularly unrewarding treasures. You search among seemingly random letters till you find the words that were laid in backward and forward, up and down, and diagonally. He had long since learned that all you do is move your eye back and forth, up and down on every line, finding words. Like plowing a field or mowing a lawn—not that Dabeet had ever done either task.
Only there weren’t any words on any of the lines in any language Dabeet knew. Just a bunch of letters.
“Our old friend” meant nothing to Dabeet—they had no “old friend” unless she meant MinCol himself, which was highly unlikely, since she wouldn’t have concealed his name, she would have used it openly, as a brag. So she might—must—be referring to the South Americans. As far as Dabeet knew, she hadn’t met them when he left for Fleet School, but if they made themselves known to her, it would be in the guise of friends of Dabeet’s. Unless they openly told her that she was their hostage for Dabeet’s good behavior. It’s not as if they were subtle men.
Dabeet received the letter at bedtime, when he was putting away his desk; it was a physical, paper letter in his mother’s own hand, which meant that it had waited on Earth until a shuttle could take it on its regular rounds, probably first to the Moon and then from the Moon to Fleet School. The most important and least important messages traveled that way. But in this case, Dabeet assumed that the South Americans wanted it that way—probably so he would see Mother’s handwriting on the letter. The puzzle, though, was a computer printout.
Dabeet tried reading something into every line in every direction but before long he had to conclude that this was a cipher. It couldn’t be a code, because he had been given no key; they must expect him to realize there was a letter-for-letter cipher and figure it out on his own.
They knew he was smart, so they wouldn’t need to make it so obvious that some teacher or military censor could see that it was anything but a puzzle. If they looked closely, they’d see that there were no recognizable words and so they might get suspicious. But of course any adult at Fleet School who saw a puzzle that had been sent by a mother to her child wouldn’t bother trying to solve it.
It really was a puzzle. A different kind of word search. It’s just that all the letters had been switched out with other letters.
If it was language, then he should be able to pick up patterns that looked like words and sentences. There were no spaces, of course, but there should be letters that were particularly common in each language, and he could make guesses.
How intelligent was the creator of this cipher? The goal wasn’t to make it uncrackable, because any cipher could be broken by brute-force computing. The goal was to hide the fact that it was a ciphered message, but then make it easy to crack so there was no chance that Dabeet would miss any part of the message.
Whatever Dabeet did, he would need to rely on the power of his desk to help him. He scanned the puzzle into his desk and told the desk to treat the puzzle as individual letters, but keep the shape of the puzzle and not “correct” anything that looked like it was trying to be a word.
How would Dabeet himself create a bilingual cipher to a kid without a key?
He would choose a non-obvious direction and run the entire message consistently in that direction, maybe from bottom to top, right to left. Or perhaps one of the diagonals. They might use boustrophedon inscription, putting one line right to left, the next line left to right, as you would plow a field, back and forth in alternating directions.
Then there was the problem of part of the message being in Spanish, part in English—if that’s what Mother’s letter meant. Dabeet looked up character frequency in both languages and found that they were quite different. E led the way in both languages, but in Spanish the frequency went down from there as E, A, O, S, N, R, I, L, D, T, U. In English, it was E, T, A, I, N, O, S, H, R, D, L, U.
In a message this short, though, there was no guarantee that the frequency of letters would conform to the norms for the whole of literature.
And Dabeet’s source on Spanish separated regular vowels and consonants from those with accent and tilde marks. The cipher couldn’t use separate characters to stand for N and ?, along with two characters for every vowel, because they’d run out of letters in the English alphabet. So “se?or” would be enciphered as “senor” and “aquí” as “aqui.” Easy enough. Most Hispanics in America had long since stopped bothering with accent marks online, because it was such a bother on keyboards designed for American English.
The rule with simple ciphers was, of course, to first find the Es. A simple count of each character indicated two candidates for E. Letters D and U were fairly evenly matched in the cipher, with a slight edge for U. Dabeet then scanned the lines and columns and diagonals to see which direction looked more plausible.
None of them looked right. Whether he used D or U, there were formations that were impossible in both languages. Spanish and English both allow two Es in a row, but neither language ever allowed three. Neither language allowed any letter to be tripled. Yet in every direction, one letter or another was tripled. There was no direction in which he could scan the lines and detect a wordlike pattern.
Why would they make it so needlessly hard? He even tried spiraling in toward the center and still found impossible combinations.