TheCodeBreakers
as much of the message as he can with his equivalents and then
guessing what the missing letters might be. Suppose that he has
recovered e, t, and h. Inserting these values at one point he finds the
partial plaintext the?e. He can assume that the missing letter is probably
r or s and can test these assumptions at other points in the cryptogram.
The one that yields intelligible plaintext is the correct one. Thus he
continues until the entire cryptogram is solved.
Monoalphabetic substitution is today a trivial form of cipher. But the
technique of its solution lies at the heart of the cryptanalysis of nearly all
more sophisticated substitution ciphers. Their solution consists in large
measure of breaking down the cipher until the method for solving
monoalphabetic substitutions can be applied. That method is therefore of
fundamental importance.
4. The Rise of the West
MODERN WESTERN cryptology emerged directly from the flowering of
modern diplomacy
annaabi.ee 
