Python Case Study - Cryptography

Overview

This course offers a hands-on, case study-driven introduction to classical and modern cryptography using Python. Through a progression of real-world cipher implementations, learners will understand foundational encryption principles, apply cipher algorithms programmatically, and analyze vulnerabilities in both classical and modern encryption schemes. Starting with basic reverse and Caesar ciphers, the course advances through brute force attacks, transposition techniques, and affine-based cryptography before culminating in public key cryptosystems like RSA. Learners will gain practical experience in building encryption and decryption tools, evaluating cryptographic strength, and creating secure systems using libraries like PyCrypto. By the end of the course, learners will be able to construct, experiment with, and critically evaluate cryptographic systems for secure communication using Python programming, while also demonstrating fluency in key cryptographic concepts such as hashing, key generation, and symmetric vs. asymmetric encryption.

Syllabus

Foundations of Cryptography with Python

This module introduces the fundamental concepts of cryptography and explains the importance of using Python as a tool to implement and explore basic cipher techniques. Learners will gain an understanding of how cryptography works and begin experimenting with simple encryption schemes.

Brute Force and Transposition Ciphers

This module explores brute force attacks and introduces transposition ciphers. Learners will understand the mechanisms behind these techniques, implement encryption and decryption programs, and analyze cipher weaknesses through automated English detection.

Classical and Affine Ciphers

This module delves into classical encryption methods including the multiplicative and affine ciphers. Learners will build modular arithmetic utilities, encrypt and decrypt messages, and evaluate cryptographic strength based on key structure and inverses.

Substitution, Vernam & Vigenère Ciphers

This module focuses on more complex symmetric encryption techniques such as substitution, Vernam (one-time pad), and Vigenère ciphers. Learners will implement and test these ciphers, and understand their cryptographic strength and vulnerabilities.

Modern Cryptography & RSA Implementation

This module transitions to modern cryptographic techniques including Base64 encoding, hashing algorithms, and public-key cryptography using RSA. Learners will implement secure communication protocols, work with key generation, and understand the mathematics behind prime factorization and encryption algorithms.