Cracking Codes with Python 2nd Edition

Cracking Codes with Python teaches complete beginners how to program in the Python programming language. The book features the source code to several ciphers and hacking programs for these ciphers. The programs include the Caesar cipher, transposition cipher, simple substitution cipher, multiplicative & affine ciphers, Vigenere cipher, and hacking programs for each of these ciphers. The final chapters cover the modern RSA cipher and public key cryptography. Cracking Codes with Python is the 2nd edition of the previously-titled book, Hacking Secret Ciphers with Python.

Many books teach beginners how to write secret messages using ciphers. A couple of books teach beginners how to hack ciphers. But no books teach beginners how to program computers to hack ciphers. This book fills that gap.

This book is also for those who are curious about encryption, hacking, or cryptography. The ciphers in this book (except for the public key cipher in Chapters 23 and 24) are all centuries old, but any laptop has the computational power to hack them. No modern organizations or individuals use these ciphers anymore, but by learning them, you’ll learn the foundations cryptography was built on and how hackers can break weak encryption.

This book is also for people who have never programmed before. It teaches basic programming concepts using the Python programming language, which is one of the best languages for beginners. It has a gentle learning curve that novices of all ages can master, yet it’s also a powerful language used by professional software developers. Python runs on Windows, macOS, Linux, and even the Raspberry Pi, and it’s free to download and use.

In this book, the term hacker will be used often. The word has two definitions. A hacker can be a person who studies a system (such as the rules of a cipher or a piece of software) to understand it so well that they’re not limited by that system’s original rules and can modify it in creative ways. A hacker can also be a criminal who breaks into computer systems, violates people’s privacy, and causes damage. This book uses the term in the first sense. Hackers are cool. Criminals are just people who think they’re being clever by breaking stuff.