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Rejewski’s cyclometer

Emilie Dufresne describes how Rejewski was able to deduce the cycle structure of the permutation of the “double Enigma machine”.

In this video, Emilie explains how Rejewski was able to deduce the cycle structure of the permutation of the “double Enigma machine”, and how this dramatically reduced the number of possible encryptions from billions to thousands.

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The Mathematics of Cryptography: From Ancient Rome to a Quantum Future

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