Hacking Secret Ciphers with Python

Chapter 9 – The Transposition Cipher, Decrypting 123

DECRYPTING WITH THE

TRANSPOSITION CIPHER

Topics Covered In This Chapter:
 Decrypting with the transposition cipher
 The math.ceil(), math.floor() and round() functions
 The and and or boolean operators
 Truth tables

“When stopping a terrorist attack or seeking to

recover a kidnapped child, encountering

encryption may mean the difference between

success and catastrophic failures.”

Attorney General Janet Reno, September 1999

“Even the Four Horsemen of Kid Porn, Dope

Dealers, Mafia and Terrorists don’t worry me

as much as totalitarian governments. It’s been a

long century, and we've had enough of them.”

Bruce Sterling, 1994 Computers, Freedom, and Privacy

conference