(New page: == Application of Linearity == -- A. Translating... -- In order to translate the matrix sent to him by Alice, Bob should separate the encoded matrix into sets of 3 characters and then m...)
 
 
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== Application of Linearity ==  
 
== Application of Linearity ==  
  
-- A. Translating... --
+
== A. Translating... ==
  
 
In order to translate the matrix sent to him by Alice, Bob should separate the encoded matrix into sets of 3 characters and then multiply it by the inverse of the matrix originally provided to him by Alice.
 
In order to translate the matrix sent to him by Alice, Bob should separate the encoded matrix into sets of 3 characters and then multiply it by the inverse of the matrix originally provided to him by Alice.
  
-- B. Eve-sdropping --
+
== B. Eve-sdropping ==
  
 
Without the inverse of the matrix, there isn't any way that Eve could figure out what Bob and Alice were talking about. However, she has the necessary information to figure out what the inverse of the matrix is.
 
Without the inverse of the matrix, there isn't any way that Eve could figure out what Bob and Alice were talking about. However, she has the necessary information to figure out what the inverse of the matrix is.
  
-- C. Decrypting --
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== C. Decrypting ==
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 +
First you have to find the inverse of the matrix. It turns out to be:
 +
 
 +
<math>A=\left[ \begin{array}{ccc}
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-\frac{2}{3} & 0 & \frac{2}{3} \\
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0 & 1 & 0 \\
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4 & 0 & -1 \end{array} \right] \rightarrow A^{-1}=
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\left[ \begin{array}{ccc}
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\ \frac{1}{2} & 0 & \frac{1}{3} \\
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0 & 1 & 0 \\
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2 & 0 & \frac{1}{3} \end{array} \right]
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</math>
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After you find the inverse of the matrix, multiply the inverse by [ 2 23 3 ] to find the encoded message.
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 +
After decoding the matrix, I got the letters "BWE"

Latest revision as of 06:18, 19 September 2008

Application of Linearity

A. Translating...

In order to translate the matrix sent to him by Alice, Bob should separate the encoded matrix into sets of 3 characters and then multiply it by the inverse of the matrix originally provided to him by Alice.

B. Eve-sdropping

Without the inverse of the matrix, there isn't any way that Eve could figure out what Bob and Alice were talking about. However, she has the necessary information to figure out what the inverse of the matrix is.

C. Decrypting

First you have to find the inverse of the matrix. It turns out to be:

$ A=\left[ \begin{array}{ccc} -\frac{2}{3} & 0 & \frac{2}{3} \\ 0 & 1 & 0 \\ 4 & 0 & -1 \end{array} \right] \rightarrow A^{-1}= \left[ \begin{array}{ccc} \ \frac{1}{2} & 0 & \frac{1}{3} \\ 0 & 1 & 0 \\ 2 & 0 & \frac{1}{3} \end{array} \right] $

After you find the inverse of the matrix, multiply the inverse by [ 2 23 3 ] to find the encoded message.

After decoding the matrix, I got the letters "BWE"

Alumni Liaison

Correspondence Chess Grandmaster and Purdue Alumni

Prof. Dan Fleetwood