GUW   SHLXFHC   XJSXZWJG   FO  

GUW   ZFT   XJ   GUW    JXTUG – GXPW

Above is the title of one of my favourite books, encrypted.

To crack it, start looking for patterns, bearing in mind the following facts about written English:

The most common letters:             E, T, A, O, I, N, S, H, R 

Most common starting letters:      T, O, A, W, B, C, D, S, F, R

Most common finishing letters:     E, S, T, D, N, R, Y, F, L, O

Most common words:                      THE, BE, TO, OF, AND, A, IN, THAT, HAVE, I

Do you see the repeated GUW?

That is most likely to be the most common word in the language, the, so that’s what we’d try first.

If G stands for t, U stands for h and W stands for e in that word, they will do so everywhere in the cipher. So we replace all of them to get to:

Stage A