Code of the Week!

view of the enigma machine

For your chance to win your very own signed copy of Simon Singh's Code Book try out your codebreaking skills with the "Code of the Week".

Solution for the "Code of the Week!" week starting 3rd December 2007

Week 3 "a love story"

Rail Fence Cipher 

Shift = 3

The X's that people sometimes put at the end of letters or notes to mean a kiss, actually started when Lords would sign their names at the end of documents to other important people. It was originally a cross that they would kiss after signing to signify that they were faithful to God and their King. Over the years though, it slanted into the X

A Love Story

Ciphertext: 

TXTTOEMISTTEOEEOOSMNI,TLSRDEOSUSNENETEDDUNTTRPTT OETSINLCSHTYUKSTSNGSNYAHWEIFTONHRNOREATU,SNDTHH' HPPSEMPAHNFTRRTTEASAULTTWNRWLITIASTEOOMTOHIOAPP. WOGAYRSAHWLIAEIITIITTEEFTUODDEKGVTYRHGILTIOEESAEL OTEUTEDLTSNEOAKSCAYAEHLDODGHRMAHNFCESOEMRNELIA RILAOTTEODSFRGNOGFHTYRAHLGATII.EHESOHTAENTX

Code of the Week 3 (week starting 3rd December 2007)

Rail Fence Cipher 

The Rail Fence Cipher involves writing messages so that alternate letters are written on separate upper and lower lines. To create the final encrypted message, the sequence of letters on the upper line is then followed by the sequence on the lower line. The code maker improves the security of the cipher by choosing more than two lines to encrypt the message.  

Take the plaintext "pancakes for breakfast" for example.  It can be enciphered using a shift of two by writing it as follows:

pancakes rail fence cypher

The ciphertext is then created by reading across the rows as follows: 

Ciphertext: pnaefrra fsa cksobekat 

In this case, a shift of two was used ie.  two lines. In order to decipher it, the ciphertext must be split into two parts. If the shift was three, then the ciphertext must be split into three lines, four lines for a shift of four etc.

More information on the railfence cipher can be found at here (http://www.simonsingh.net/The_Black_Chamber/railfence.html)>

Good luck! 

"A Love Story"

Ciphertext: 

TXTTOEMISTTEOEEOOSMNI,TLSRDEOSUSNENETEDDUNTTRPTT OETSINLCSHTYUKSTSNGSNYAHWEIFTONHRNOREATU,SNDTHH' HPPSEMPAHNFTRRTTEASAULTTWNRWLITIASTEOOMTOHIOAPP. WOGAYRSAHWLIAEIITIITTEEFTUODDEKGVTYRHGILTIOEESAEL OTEUTEDLTSNEOAKSCAYAEHLDODGHRMAHNFCESOEMRNELIA RILAOTTEODSFRGNOGFHTYRAHLGATII.EHESOHTAENTX