Shadow of the Hegemon (The Shadow 2)

"Why in the world are you paying attention to this?" asked Carlotta.

He looked up to see her watching him.

"I don't know. Why are you paying attention to the way I'm paying attention to it?" He grinned at her.

"Because you think it matters. I may not be as smart as you are about most things, but I'm very much smarter than you are about you. I know when you're intrigued."

"Just the juxtaposition of the image of a dragon with the word 'end.' Endings really aren't considered all that lucky. Why wouldn't the person write 'luck will come' or 'lucky fate' or something else? Why 'lucky end'?"

"Why not?"

"End. Ender. Ender's army was Dragon."

"Now, that's a little far-fetched."

"Look at the drawing," said Bean. "Right in the middle, where the bitmap is so complicated--there's one line that's damaged. The dots don't line up at all. It's virtually random."

"It just looks like noise to me."

"If you were being held captive but you had computer access, only every bit of mail you sent out was scrutinized, how would you send a message?" asked Bean.

"You don't think this could be a message from--do you?"

"I have no idea. But now that I've thought of it, it's worth looking at, don't you think?"

By now Bean had pasted the dragon image into a graphics program and was studying that line of pixels. "Yes, this is random, the whole line. Doesn't belong here, and it's not just noise because the rest of the image is still completely intact except for this other line that's partly broken. Noise would be randomly distributed."

"See what it is, then," said Carlotta. "You're the genius, I'm the nun."

Soon Bean had the two lines isolated in a separate file and was studying the information as raw code. Viewed as one-byte or two-byte text code, there was nothing that remotely resembled language, but of course it couldn't, could it, or it would never have got out. So if it was a message, then it had to be in some kind of code.

For the next few hours Bean wrote programs to help him manipulate the data contained in those lines. He tried mathematical schemes and graphic reinterpretations, but in truth he knew all along that it wouldn't be anything that complex. Because whoever created it would have had to do it without the aid of a computer. It had to be something relatively simple, designed only to keep a cursory examination from revealing what it was.

And so he kept coming back to ways of reinterpreting the binary code as text. Soon enough he came upon a scheme that seemed promising. Two-byte text code, but shifted right by one position for each character, except when the right shift would make it correspond with two actual bytes in memory, in which case double shift. That way a real character would never show up if someone looked at the file with an ordinary view program.

When he used that method on the one line, it came up as text characters only, which was not likely to happen by chance. But the other line came up random-seeming garbage.

So he left-shifted the other line, and it, too, became nothing but text characters.

"I'm in," he said. "And it is a message."

"What does it say?"

"I haven't the faintest idea."

Carlotta got up and came to look over his shoulder. "It's not even language. It doesn't divide into words."

"That's deliberate," said Bean. "If it divided into words it would look like a message and invite decoding. The easy way that any amateur can decode language is by checking word lengths and the frequency of appearance of certain letter patterns. In Common, you look for letter groupings that could be 'a' and 'the' and 'and,' that sort of thing."

"And you don't even know what language it's in."

"No, but it's bound to be Common, because they know they're sending it to somebody who doesn't have a key. So it has to be decodable, and that means Common."

"So they're making it easy and hard at the same time?"

"Yes. Easy for me, hard for everyone else."

"Oh, come now. You think this was written to you?"