Part III Projects - Codes
To start you off on this project I suggest you read Simon Singh' "The Code Book". You can alsodownload an accompanying CD from his web site at www.simonsingh.net. You should also read the
Introduction document and tackle the problems in it.
Text files for the ciphers in the Introduction document
Excel deciphering programme
To help you with deciphering the second cipher is an Excel spread sheet I have written. This uses Visual Basic and you should be able to adapt it (get out you Part I notes!!!) to help with other ciphers. It is already loaded with Cipher 2 to get you going.
It should be self explanitary to use, the only sticking point is that you have to finish entering information in a box (click elsewhere or hit return) before you can click on a button. Also I have protected areas on the sheet to prevent unintentional editing. To alter you will have to turn this protection of (see under Tools).
I have also done a second Excel spreadsheet here which counts pairs of letters. This is useful in, for example, solving the Playfair cipher.
Individual Ciphers
Your individual ciphers can be found here. Each of you have a letter. Use the ciphers that end in that letter.
Additional ciphers
These additional ciphers are not discussed in any of the associated documentation. The first is another basic cipher (with only 25 keys). This is actually equivalent to a special case of one of the other ciphers already looked at. The other two combine it with a Monoalphabetic substitution cipher in different orders.
Frequency Tables
Fortran programmes
You may use or adapt these if you like. They can be run on the University machines that use the Linux operating system.