Cracking Codes with Python

6HACKING THE CAESAR CIPHER WITH BRUTE-FORCE

“Arab scholars . . . invented cryptanalysis, the science of unscrambling a message without knowledge of the key.”—Simon Singh, The Code Book

We can hack the Caesar cipher by using a cryptanalytic technique called brute-force. A brute-force attack tries every possible decryption key for a cipher. Nothing stops a cryptanalyst from guessing one key, decrypting the ciphertext with that key, looking at the output, and then moving on to the next key if they didn’t find the secret message. Because the brute-force technique is so effective against the Caesar cipher, you shouldn’t actually use the Caesar cipher ...