Breaking Simple Substitution Ciphers   

1. What are the projects? 

   It is to decrypt a given piece of ciphertext, obtained by encrypting  

   an English essay with a simple substitution cipher. Your task is to 

   recover the original writing in English. 

2. About the ciphertexts 

   In each piece of ciphertext, I deleted the blank space between certain 

   words. But the blank space between certain worlds is kept. This is to 

   make the project neither too easy nor too hard. 

   In the ciphertext "XPIOMAZ DZFQEEQEF", X and Z must be the beginning 

   and end of some words, but "XPIOMAZ" may be obtained from one English 

   word or more than one words. 

   Punctuation is kept, and special symbols such as 2005 are not encrypted. 

3. How to decrypt the ciphertext? 

   (A) You should use the uneven distribution of signle English letters, 

       of digrams (for example, "th" appears the most). 

   (B) For frequency analysis, you may use the software at the URL: 

       http://www.cryptoclub.org/tools/crack_substitutioncipher.php

       Alternatively, you may write your own computer programs for breaking the ciphers. 

   (C) Make use of short words, pay attention to the beginning and end 

       of words. Special symbols such as "1995 WRT 2005" give you very 

       quick information. 

   (D) Materials about classical ciphers can be found in: 

       http://www.cs.ust.hk/emb/itepc2006/itepc04/