Book Image

Hands-On Cryptography with Python

By : Samuel Bowne
Book Image

Hands-On Cryptography with Python

By: Samuel Bowne

Overview of this book

Cryptography is essential for protecting sensitive information, but it is often performed inadequately or incorrectly. Hands-On Cryptography with Python starts by showing you how to encrypt and evaluate your data. The book will then walk you through various data encryption methods,such as obfuscation, hashing, and strong encryption, and will show how you can attack cryptographic systems. You will learn how to create hashes, crack them, and will understand why they are so different from each other. In the concluding chapters, you will use three NIST-recommended systems: the Advanced Encryption Standard (AES), the Secure Hash Algorithm (SHA), and the Rivest-Shamir-Adleman (RSA). By the end of this book, you will be able to deal with common errors in encryption.
Table of Contents (9 chapters)

Strong encryption with AES

In this section, we will take a look at the Advanced Encryption Standard (AES), private key encryption, key and block size, how to influence AES, and Python and confusion and diffusion.

AES is the encryption standard approved by the United States National Institute of Standards and is considered very secure. It's approved even for the storage of secret military information. It is private key cryptography, which is the kind of cryptography that has been used for thousands of years in which both the sender and the receiver use the same key. It's a block cipher, so the input data has to be put in blocks that are 128-bits long, and a block of plaintext is encrypted with a key, producing a block of ciphertext:

There are three key sizes: 128, 192, and 256-bits. The most common type of AES is the 128-bit key size, and that's what we'll use in this example. In Python, it's quite easy to use.

Firstly, you need to import the AES module from crypto cipher, then you need a 16...