substitution cipher
http://plus.maths.org/content/taxonomy/term/278
enCracking codes
http://plus.maths.org/content/cracking-codes
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Artur Ekert </div>
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In the first of two articles, <b>Artur Ekert</b> takes a tour through the history of codes and the prospects for truly unbreakable quantum cryptography. </div>
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<div class="pub_date">March 2005</div>
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<p><i>"Few persons can be made to believe that it is not quite an easy thing to invent a method of secret writing which shall baffle investigation. Yet it may be roundly asserted that human ingenuity cannot concoct a cipher which human ingenuity cannot resolve..."</i></p>
<p align="right"><i>Edgar Alan Poe - "A few words on secret writing"; 1841</i></p><p><a href="http://plus.maths.org/content/cracking-codes" target="_blank">read more</a></p>http://plus.maths.org/content/cracking-codes#comments34Bletchley ParkCaesar shift cipherEnigmafrequency analysisone-time padpolyalphabetic cipherscytalesubstitution cipherVernam cipherTue, 01 Mar 2005 00:00:00 +0000plusadmin2263 at http://plus.maths.org/contentDecoding a war time diary
http://plus.maths.org/content/decoding-war-time-diary
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P.J. Aston </div>
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An account of how a prisoner of war's diary was recently decoded. Donald Hill wrote his diary in a numerical code, disguised as a set of mathematical tables, while in Hong Kong during and after the Japanese invasion of 1941. </div>
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<div class="pub_date">September 1997</div>
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<p>Donald Hill was a young squadron leader attached to the Far East command in Kai Tak, Hong Kong in 1941. The Japanese attacked on 8 December and seventeen days later, on Christmas day, the outnumbered defending forces surrendered and were put into prisoner of war camps in which many died. Donald kept a diary during the battle and for a time during his captivity. He wrote it in a numerical code,
disguised as "Russels Mathematical Tables".<p><a href="http://plus.maths.org/content/decoding-war-time-diary" target="_blank">read more</a></p>http://plus.maths.org/content/decoding-war-time-diary#comments3frequencysubstitution ciphertransposition cipherSun, 31 Aug 1997 23:00:00 +0000plusadmin2150 at http://plus.maths.org/content