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Basic code breaking starts with analyzing letter frequency. You don't really need to know the percentages given on the table of the previous page, Secret Codes. It's more useful to just arrange the letters in order of prevalence, as they are here:
Code breaking can begin then with identifying the most frequent letter or number in a message and replacing each of these with an "e", since that is the most frequent letter in English. The letter "t" or "a" would be tried next, if the "e" didn't seem to work. Alternately, you can simply list all the letters, symbols or numbers being used and count each one, then try using "e" "t" or "a" in place of any of the top five or six.
For example, in the message below, charting the letters would show that the most frequent six are, in order of prevalence: b, x, a, g, h, and w. We can be fairly sure that one of these is "e" and it is even likely that "t" and "a" are among the top six (but not always).
The message:
qt mak xgb gbxcqwr hpqi, eawrgxhkyxhqawi! qt mak exw sgbxz hpqi eacb, mak xgb gbxcm tag hpb eacb sgbxzgwr epxyybwrbi qw hpb rgbxh eayagxca hgbxikgb pkwh. wal mak sbhhbg rbh skim xwc tqwc x hgbxikgb!
Now, we can try replacing every "b" with "e," since there are 20 incidents of "b," which is four more than the next most frequent code letter. When doing this, write the original message with double or triple spacing, so there is room to pencil-in several possibilities. Before we go any further, though, lets look at some facts that will help with any code breaking. Here are the most common words with:
One letter: a and I.
Two letters: am, an, as, at, be, by, do, go, he, if, in, is, it, me, my, no, on, or, so, to, and we.
Three letters: and, are, but, can, how, now, the, was, and you.
Looking at the message, we see there is just one word that has one letter, and that is "x." It could be "i," but "a" is more likely, so we'll try that. There is a three letter word starting with "x" (xwc), which if "x" is "a" is most likely "and." That gives us two more deciphered letters (w=n and c=d) if our assumptions are correct. By the way, if assumptions are proven wrong, you just start over with new ones, playing the odds as best as you can.
Let's look at what the message looks like once we replace "b" with "e," "x" with "a," "w" with "n," and "c" with "d":
qt mak age geadqnr hpqi, eanrgahkyahqani! qt mak ean sgeaz hpqi eade, mak age geadm tag hpe eade sgeazgnr epayyenrei qn hpe rgeah eayagada hgeaikge pknh. nal mak sehheg reh skim and tqnd a hgeaikge!
Now we look at any two and three letter words which have our deciphered letters in them. There are a couple that read "hpb" in the original, and now that we are assuming "b" is "e," it makes sense that these would be the most common three letter word, 'the." Thus we can assume that "h" is "t" and"p" is "h."
Code breaking consist of these little steps, so you just continue in this way. There may be tool in your computer that can help you. A spell checker, for example, can replace every "hpb" with "the" if you highlight the first one, enter "the" and click the "change all" option. Do this repeatedly as you decipher other words.
Also, if you have an idea that a particular word may be in the message, find the coded words with the same number of letters to see if they fit your theory. Given the nature of this site, it's a good bet that the word "treasure" is in this message, so look for eight-letter words. There are three, and two fit the assumed letters we have deciphered, making it almost certain that "hgbxikgb" is the word "treasure," which gives us three more letters. At this point it gets pretty easy.
This is the code used to create the message:
a=o, b=e, c=d, d=p, e=c, f=q, g=r, h=t, i=s, j=v, k=u, l=w, m=y, n=x, o=z, p=h, q=i, r=g, s=b, t=f, u=j, v=m, w=n, x=a, y=l, z=k,
Here is the coded message again, followed by the deciphered version:
qt mak xgb gbxcqwr hpqi, eawrgxhkyxhqawi! qt mak exw sgbxz hpqi eacb, mak xgb gbxcm tag hpb eacb sgbxzgwr epxyybwrbi qw hpb rgbxh eayagxca hgbxikgb pkwh. wal mak sbhhbg rbh skim xwc tqwc x hgbxikgb!
If you are reading this, congratulations! If you can break this code, you are ready for the code breaking challenges in the Great Colorado Treasure Hunt. Now you better get busy and find a treasure!
If I have an error or two, I have an excuse as well. If this were truly meant to be a secret message meant only for a trusted associate, a few errors wouldn't cause any problem for that person, any more than a few misspellings do. The receiver, after all, normally has the key. But errors do make code breaking more difficult for the code breaker. Therefore, as a code maker it actually makes sense to be sloppy, since it enhances security.