POW#1 Spring 2022

Solutions due by noon on Friday, February 4

Alice encrypts a message M (the cleartext) into the encrypted message C (the ciphertext) and then transmits C to Bob. (It’s always Alice and Bob in these stories).

Eve intercepts the transmission and finds that
C = pivtskriqkxertknirtkmdodxrvhkisodmiqditqpoktkmokmdo

Eve has some knowledge about the kinds of messages that Alice likes to send and knows that the most frequent character Alice uses is t. In fact Eve knows the relative frequencies of all the characters that Alice uses, in the following list, ordered from most frequent to least frequent teacsimndoprfhubgjklqvwxyz

What was the original message M that Alice sent to Bob?

This problem is brought to you by Prof. Ed Harcourt.

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