(New page: == Bob can decode the message == All Bob has to do is invert the matrix and multiply the code with this inverted matrix 3 numbers at a time. Finally he can obtain the message by convertin...)
 
(Eve can decode the message without the Secret vector)
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All Bob has to do is invert the matrix and multiply the code with this inverted matrix 3 numbers at a time. Finally he can obtain the message by converting each number to it's corresponding alphabet character.
 
All Bob has to do is invert the matrix and multiply the code with this inverted matrix 3 numbers at a time. Finally he can obtain the message by converting each number to it's corresponding alphabet character.
  
== Eve can decode the message without the Secret vector ==
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== Eve can decode the message without the secret matrix's inverse ==
  
 
Since she knows both the original message and the decrypted version, she doesn't really need the secret matrix to find the original does she? She already has it! All she has to do is think about it, perhaps meditate on the matter, and realize that each number corresponds directly to a letter in the alphabet.
 
Since she knows both the original message and the decrypted version, she doesn't really need the secret matrix to find the original does she? She already has it! All she has to do is think about it, perhaps meditate on the matter, and realize that each number corresponds directly to a letter in the alphabet.

Revision as of 07:28, 18 September 2008

Bob can decode the message

All Bob has to do is invert the matrix and multiply the code with this inverted matrix 3 numbers at a time. Finally he can obtain the message by converting each number to it's corresponding alphabet character.

Eve can decode the message without the secret matrix's inverse

Since she knows both the original message and the decrypted version, she doesn't really need the secret matrix to find the original does she? She already has it! All she has to do is think about it, perhaps meditate on the matter, and realize that each number corresponds directly to a letter in the alphabet.

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Basic linear algebra uncovers and clarifies very important geometry and algebra.

Dr. Paul Garrett