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April 13, 2009 in
Every Easter the Easter Bunny visits our house, leaving a trail of plastic eggs containing slips of paper. The slips of paper contain clues to the location of presents for the kids (Easter was never this big a deal when I was little).
This year the first egg, left in a prominent location, contained a clue (a rhyme, suitable for a five-year-old) to the location of another, which in turn contained a clue to the location of the next, and so on until the pieces fit together to make an 8.5X11 sheet.
On the back of the sheet, once the pieces were assembled, was the following:
I figured it would take her half an hour or so with my help.
It took her 30 seconds to break the code. Thirty seconds.
When I saw how she had done it, my first thought was that she had made a couple of unwarranted assumptions.
But winning is often about making correct assumptions that your adversary thinks are unwarranted. In other words, the Easter Bunny was flat-out outsmarted.
That rabbit’s going to have to bring his “A” game next year.
Well, I’m not smarter than a third grader. It took me a few minutes to figure out the cipher—even with the clue that it’s easy for a child to guess—and I still have no idea what the clue is to fill in that final crucial blank word.
And yes, you have a really smart daughter. But I’ll bet you could stump her with a Caesar cipher! For the next couple of years, anyway.
If you knew that Casa Bennett had a tower, you might be able to find the Easter basket too.
Not speaking as an 8 year old, obviously, but the real key to figuring out the cipher quickly is to notice the two letters used for single words, n and v. There are only 2 one-letter words in the whole language, “a” and “I”, and both are in the cipher text. Plus, grammar orders one of those words to capitalized, so you can tell which is which if the writer followed the rules of proper grammar.
Once you figure out what n and v are, it’s pretty trivial to find the rest of the cipher.
If you can write a cipher text that doesn’t include any single letter words, you can make it more difficult to recognize what the cipher is, or at least by including only one of the two words, which means you at least have to play out both scenarios to see which one seems to fit better(which can be tricky because of it/at, in/an, is/as, etc.) You can also try to avoid using “I” and “a” as anything but the first word in a sentence, so that it’s not immediately apparent which is which based on grammar rules, or just ignore the proper capitalization of “I”.
She got “a” and then made the unwarranted but correct assumption that this was a rotation cipher, so that if N was a then A was n and B was o and so forth.
For the text, the Easter Bunny chose the first four paragraphs of “Alice’s Adventures in Wonderland.” She didn’t need to decrypt more than the first word to make that unwarranted but correct assumption.
Turns out, of course, that Lafferty was wrong, and that “Primary Education of the Camiroi” was a documentary, not fiction. :)
As you probably know, this is the ROT-13 cipher that was commonly used for the Usenet newsgroup system. The name just means ROTate 13 letters—half way around the alphabet. The goal was not security, but just to hide information from a casual glance. For example, when posting a movie review, spoilers could be hidden by ROT-13 so that readers wouldn’t inadvertently learn things they didn’t want to know. News readers could toggle messages between plaintext and ROT-13 with a keystroke.
Nowadays we accomplish the same thing with multiple web pages or with javascript.
Easter wasn’t such a big deal when Mark was little.
Where he lived Shivarathri, Loy Krathong, Diwali and Ashura were all bigger. No inflatable Easter Bunnies but lots of floggings, Tibetan monks chanting, and water rituals.