"Computing Machinery and Intelligence"

Mind: A Quarterly Review of Psychology and Philosophy, Volume LIX, Number 236: October 1950

Standard Written English
 

E	the highest frequency
T A O I N S H R	high frequency group
D L	medium frequency
C U M W F G Y P B	low frequency
V K J X Q Z	rare

 

With a Caesar Cipher, we only need to know where one letter goes to find the key.

For Caesar Cipher: Guess that E was shifted to the most frequent letter and try this shift as the key. Your guess should also be consistent with the following observations about standard written English:

Among High Frequency Letters:

A, E, I are 4 apart (equally spaced)

R, S, T from a consecutive triple

Among Low Frequency Letters;

V, W, X, Y, Z are 5 consecutive lows.

Part 2