Cipher Help
A cipher is a way to transforming a message so that it can not be easily read. The encrypted message is called a cryptogram or ciphertext. A substitution cipher is one in which each letter of the plaintext is replaced by some other symbol. Usually the replacement symbols are themselves letters of the alphabet, but they don't always have to be.
Solving substitution ciphers might seem hard at first, especially when you don't have any clues to go by, but it's usually not really so difficult once you get started. The key is to look for familiar elements. For instance, look for two-letter words, which most likely will be words like in, of, it, to, is, and so on. Also, look for double letters within words, which most likely will be oo, ss, ee, etc.
If you see the same three-letter word combination more than once within a phrase, chances are good that it will be the word the, although other words are possible. It also helps to remember the frequency with which we use letters of the alphabet. If you see one letter used more often than any others, chances are it's E or T.
The best thing to do is just plunge ahead with a hunch and see if it leads you anywhere. Copy the ciphers onto paper and play with some letter combinations. For instance, if you think a particular letter equals E, write an E above all those letters and work from there. You might have to back up and try another letter, but that's all part of the fun!
Here are a few tips about the normal frequency of different letter combinations in the English language that will help you in your quest...
Order of frequency of single letters
E T O A N I R S H D L C W U M F YG P B V K X Q J Z
Order of frequency of digraphs (two letter combinations)
th er on an re he in ed nd ha at en es of or
nt ea ti to it st io le is ou ar as de rt ve
Order of frequency of trigraphs
the and tha ent ion tio for nde has nce edt tis oft sth men
Order of frequency of most common doubles
ss ee tt ff 11 mm oo
Order of frequency of initial letters
T O A W B C D S F M R H I Y E G L N P U J K
Order of frequency of final letters
E S T D N R Y F L O G H A R M P U W
One-letter words
a, I, 0.
Most frequent two-letter words
of, to, in, it, is, be, as, at, so, we, he, by,
or, on, do, if, me, my, up, an, go, no, us, am...
Most frequent three-letter words
the, and, for, are, but, not, you, all, any, can,
had, her, was, one, our, out, day, get, has, him,
his, how, man, new, now, old, see, two, way, who,
boy, did, its, let, put, say, she, too, use...
Most frequent four-letter words
that, with, have, this, will, your, from, they,
know, want, been, good, much, some, time, very,
when, come, here, just, like, long, make, many, more,
only, over, such, take, than, them, well, were...