After reading (almost done) with:

The Code Book : The Secret History of Codes and Code-Breaking Paperback – April 30, 2002
by Simon Singh (Author) available at Amazon and so on

I became fascinated with the history and the small stories that goes along with the different codes used and still being used today.

Here is a link for viewing and programming cryptography:

https://www.tutorialspoint.com/cryptography_with_python/cryptography_with_python_caesar_cipher.htm

Overview
Double Strength Encryption
Python Overview and Installation
Reverse Cipher
Caesar Cipher
ROT13 Algorithm
Transposition Cipher
Encryption of Transposition Cipher
Decryption of Transposition Cipher
Encryption of files
Decryption of files
Base64 Encoding & Decoding
XOR Process
Multiplicative Cipher
Affine Ciphers
Hacking Monoalphabetic Cipher
Simple Substitution Cipher
Testing of Simple Substitution Cipher
Decryption of Simple Substitution Cipher
Python Modules of Cryptography
Understanding Vignere Cipher
Implementing Vignere Cipher
One Time Pad Cipher
Implementation of One Time Pad Cipher
Symmetric & Asymmetric Cryptography
Understanding RSA Algorithm
Creating RSA Keys
RSA Cipher Encryption
RSA Cipher Decryption
Hacking RSA Cipher