7710
/www/nrich/html/content/id/7710/
1
2011-10-24T11:59:15
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<mdoxml version="1.0"><p>Have you managed to solve the entire <a href="http://nrich.maths.org/7081">Stage 5 Cipher Challenge</a>? Solutions are now closed, but perhaps you want to take up the full challenge.</p>
<p> </p>
<p>Patrick from Woodbridge School, England was the first to solve this cipher<br></br>
Joseph from Hong Kong was the only other successful solver.<br></br>
<br></br>
The solution is<br></br>
<br></br>
Congratulations if you can read this, this encryption's getting quite complicated. The vigenere method of encryption commutes with a transposition if its row and column lengths are one more than a multiple of the keyword length, so in this case with a keyword of length two we need them to both be odd. I hope you've enjoyed decrypting these messages, why not try coming up with some ciphers
yourself and testing your friends.<br></br>
<br></br>
vigenere with keyword pi<br></br>
transposition<br></br>
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<mdoxml version="1.0"><p>This challenge cipher forms part of a very difficult <a href="http://nrich.maths.org/7081">sequence of ciphers</a> suitable for keen groups or individuals, maths clubs and very optional homework challenges. Don't try this in the classroom!</p></mdoxml>
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<mdoxml version="1.0"><p>This is the seventh of our <a href="https://nrich.maths.org/7081">challenge ciphers</a>.</p>
<p>We recommend that you attempt them in order, as the solution of each challenge gives a small (and necessary!) hint for the next challenge.</p></mdoxml>
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<p> </p>
<div>Congratulations if you can read this, this encryption's getting quite complicated. The vigenere method of encryption commutes with a transposition if its row and column lengths are one more than a multiple of the keyword length, so in this case with a keyword of length two we need them to both be odd. I hope you've enjoyed decrypting these messages, why not try coming up with some
ciphers yourself and testing your friends.</div>
<div> </div>
<div>
<div> </div>
<div>vigenere with keyword pi</div>
<div>transposition</div>
<div> </div>
</div>
<p> </p>
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2
5
0
0
0
0
1
ip?
Seventh challenge cipher
Decision Mathematics and Combinatorics
Permutations
Decision Mathematics and Combinatorics
Combinatorics
Decision Mathematics and Combinatorics
Algorithms
Applications
Codes and cryptography