Drear/sir/madam 

I have been given a peace of work to do, which involves a Vigenere
Cipher in Haskell

The work has to be in Haskell, the work involves a few things like
having to display the Vigenere Cipher on the terminal and also
displaying it has its ASCII numbers

If you are interested I will scan the work, in to a word document so
you can look at it so you will understand better what I need, if you
will please give me you e-mail address I will send it to you

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Request for Question Clarification by rbnn-ga on 18 Nov 2002 08:20 PST

In order for us to answer the question, you will need either to post
the information here or point us to a URL where the information may be
found.

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Clarification of Question by amber12345-ga on 18 Nov 2002 17:43 PST

1 define a function which displays a Vigenere Square on the terminal

2 Define a function which displays a Vigenere Square has the
equivalent ASCII numbers instead of letters

3 Define a function ASCII : : Int -> Int -> Int which returns the ASCH
value of the cipher letter, given the ASCII value of a key word letter
and that of a plain text letter
Example 71 110
84 

4 Define a function Char-> Char-> Char which return the cipher letter
given a keyword and a plain text letter

Example ‘n’ ‘e’
‘R’

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Request for Question Clarification by rbnn-ga on 18 Nov 2002 18:38 PST

1. What compiler are you using? What platform?

2. I do not understand the signature 

4 Define a function Char-> Char-> Char which return the cipher letter
given a keyword and a plain text letter
 

You mention a "keyword" but your signature is only for a Char. I don't
quite understand here. Is it a one-character keyword?

You might want to post the exact definition of Vigenere cipher you are
using. Normally as I mentioned, in this cipher you are giving a
keyword (that is a [Char] not a Char) and a message (also a [Char])
and you are trying to encrypt one.

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Clarification of Question by amber12345-ga on 19 Nov 2002 07:39 PST

My e-mail address is on http://www.kasamba.com/

Under  public board Computers & Internet (19) 

my question is 

I am after help with a Vigenere Cipher, in the Haskell programming language  

You will see my e-mail address under the question, if you would please send 
Me your e-mail address, I can then send you the a scanned document so you will
Understand my question better

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Request for Question Clarification by rbnn-ga on 19 Nov 2002 09:08 PST

Hi amber,

Google Researchers are not allowed to contact questioners other than
through this board. Can you simply type in what is scanned?

If not, I will try and find a site to which you upload your image, but
I may not be able to do so.

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Clarification of Question by amber12345-ga on 19 Nov 2002 15:15 PST

i have tried to cut out has much has i can from my document which is
twelve pages long, below are sites with examples of the vigenere
square
i have a week to solve the questions below 

I am using the compiler Hugs for windows 98 from the haskell site 

http://www.greenhodge.net/g/play/crypto/vigenere-explan.shtml


http://www.trincoll.edu/depts/cpsc/cryptography/vigenere.html


Let us presume that P consists of lower case letters (a - z) only and
it is


P = ''meeting at dawn in the garden''


K consists of capital letters (A-Z) only and is assumed to be 

 K = mystery 


To encrypt the message, we align the letters of P underneath those of
(repeats of) K:

 M Y  S  T  E  R  Y  M  Y   S  T E R  Y  M   Y  S  T E  R  Y  M   Y  S
 M e  e  t  I  n  g  a  t   d  a w n  I  n   t  h  e g  a  r  d   e  n
 

Each of the above 24 pairs of letters is mapped to a letter of the
cipher text according to the Vigenere Square whose rows and columns
are accordingly indexed by upper- and lowercase letters. Respectively.
So, for example, the first pair (M , m) is mapped to Y, the second
pair ( Y , e ) is mapped to C, the third pair ( S , e ) is mapped to W
etc.







Task 1. 

Define a function: IO () which displays the Vigenere Square on the
terminal

example
Define function rotations: [a] -> [[a]] which for any list returns the
list of all its rotations

 Example 
 Define a function all-rotations Cw2002> all-rotations [1.2, 3, 4, 5]
[(1,2.3,4,5),(2,3,4,5,1),(3,4,5,1,2),(4,5,1,2,3),(5,1,2,3,4)] 

Which displays the Vigenere Square on the terminal; I have used
numbers instead of letters for this example

Complete list-of-lists representation of the Vigenere Square is
achieved by some additional steps involving mapping operations
concerned with scatting on the edges'. Then print the result.




Task 2 

  Define a function vigenere-asciI: 10 ( ) except that now each
character is represented by its respective ASCII code. Which displays
the Vigenere Square except that now each character is represented by
its respective ASCII CODE


Task 3 


Define a function ASCII c: Int -> Int -> Int: which returns the ASCII
value of the cipher letter

Given the ASCII value of a key word letter and that of a plain-text
letter   Example: prompt >    ASCII_C   7 1   110
Returns 84

Prompt >ASCII_C   85 113  

 Returns   75   



Task 4   Now use ASCII -c to define a function v-cipher: Char ->
Char-> Char

Which returns the cipher letter, given a key word letter and a plain
text letter Example

Prompt >   v cipher   ' N ‘   ‘E’ 
Returns   R 



Task 5. 

Now, use v-cipher to define the function cipher String ->String ->
String

Whose functionality has been exemplified below  

Prompt > cipher ''MYSTERY'' ''meetingatda|inthegarden'' 

''YCWMMEEMRVTAEGZRZXKRPPCF''

Prompt > decipher ''MYSTERY'' ''YCWMMEEMRVTAEGZRZXKRPPCF''
''meetingatda|inthegarden''

Sorry Amber but we are not allowed to give our personal e-mail
addresses. Just post whatever you want to show us somewhere in the
Internet and then give us the link here. That would be enough. We hope
you understand.