Learn to deploy proven cryptographic tools in your applications and services
Cryptography is, quite simply, what makes security and privacy in the digital world possible. Tech professionals, including programmers, IT admins, and security analysts, need to understand how cryptography works to protect users, data, and assets. Implementing Cryptography Using Python will teach you the essentials, so you can apply proven cryptographic tools to secure your applications and systems. Because this book uses Python, an easily accessible language that has become one of the standards for cryptography implementation, you’ll be able to quickly learn how to secure applications and data of all kinds.
In this easy-to-read guide, well-known cybersecurity expert Shannon Bray walks you through creating secure communications in public channels using public-key cryptography. You’ll also explore methods of authenticating messages to ensure that they haven’t been tampered with in transit. Finally, you’ll learn how to use digital signatures to let others verify the messages sent through your services.
• Learn how to implement proven cryptographic tools, using easy-to-understand examples written in Python
• Discover the history of cryptography and understand its critical importance in today’s digital communication systems
• Work through real-world examples to understand the pros and cons of various authentication methods
• Protect your end-users and ensure that your applications and systems are using up-to-date cryptography
Author(s): Shannon W. Bray
Edition: 1
Publisher: Wiley
Year: 2020
Language: English
Commentary: Vector PDF
Pages: 304
City: Indianapolis, IN
Tags: Programming; Python; Cryptography; Kerberos; Public-Key Cryptography; Group Theory; Hashing; Steganography; Cryptographic Protocols; Private-Key Cryptography; Elementary; Diffie-Hellman Function; X.509; Prime Numbers
Cover
Title Page
Copyright Page
About the Author
Acknowledgments
Contents at a Glance
Contents
Introduction
Chapter 1 Introduction to Cryptography and Python
Exploring Algorithms
Why Use Python?
Downloading and Installing Python
Installing on Ubuntu
Installing on macOS
Installing on Windows
Installing on a Chromebook
Installing Additional Packages
Installing Pip, NumPy, and Matplotlib
Installing the Cryptography Package
Installing Additional Packages
Testing Your Install
Diving into Python Basics
Using Variables
Using Strings
Introducing Operators
Understanding Arithmetic Operators
Understanding Comparison Operators
Understanding Logical Operators
Understanding Assignment Operators
Understanding Bitwise Operators
Understanding Membership Operators
Understanding Identity Operators
Using Conditionals
Using Loops
for
while
continue
break
else
Using Files
Understanding Python Semantics
Sequence Types
Introducing Custom Functions
Downloading Files Using Python
Introducing Python Modules
Creating a Reverse Cipher
Summary
Chapter 2 Cryptographic Protocols and Perfect Secrecy
The Study of Cryptology
Understanding Cryptography
Cryptography’s Famous Family: Alice and Bob
Diffie-Hellman
Data Origin Authentication
Entity Authentication
Symmetric Algorithms
Asymmetric Algorithms
The Needham-Schroeder Protocols
The Otway-Rees Protocol
Kerberos
Multiple-Domain Kerberos
X.509
Formal Validation of Cryptographic Protocols
Configuring Your First Cryptographic Library
Understanding Cryptanalysis
Brute-Force Attacks
Side-Channel Attacks
Social Engineering
Analytical Attacks
Frequency Analysis
Attack Models
Shannon’s Theorem
One-Time Pad
XOR, AND, and OR
One-Time Pad Function
One-Way Hashes
Cryptographic One-Way Hashes
Message Authentication Codes
Perfect Forward Secrecy
Published and Proprietary Encryption Algorithms
Summary
References
Chapter 3 Classical Cryptography
Password Best Practices
Password Storage
Hashing Passwords
Salting Passwords
Stretching Passwords
Password Tools
Obfuscating Data
ASCII Encoding
Base64 Encoding Text
Binary Data
Decoding
Historical Ciphers
Scytale of Sparta
Substitution Ciphers
Caesar Cipher
ROT-13
Atbash Cipher
Vigenère Cipher
Playfair
Hill 2x2
Column Transposition
Affine Cipher
Summary
Chapter 4 Cryptographic Math and Frequency Analysis
Modular Arithmetic and the Greatest Common Devisor
Prime Numbers
Prime Number Theorem
School Primality Test
Fermat’s Little Theorem
Miller-Rabin Primality Test
Generate Large Prime Numbers
Basic Group Theory
Orders of Elements
Modular Inverses
Fermat’s Little Theorem to Find the Inverse
Extending the GCD
Euler’s Theorem
Pseudorandomness
Breaking C’s rand() Function
Solving Systems of Linear Equations
Frequency Analysis
Cryptanalysis with Python
Using an Online Word List
Determining the Frequency
Breaking the Vigenère Cipher
Summary
Chapter 5 Stream Ciphers and Block Ciphers
Convert between Hexdigest and Plaintext
Use Stream Ciphers
ARC4
Vernam Cipher
Salsa20 Cipher
ChaCha Cipher
Use Block Ciphers
Block Modes of Operations
ECB Mode
CBC Mode
CFB Mode
OFB Mode
CTR Mode
Tricks with Stream Modes
DIY Block Cipher Using Feistel Networks
Advanced Encryption Standard (AES)
Using AES with Python
File Encryption Using AES
File Decryption Using AES
Summary
Chapter 6 Using Cryptography with Images
Simple Image Cryptography
Images and Cryptography Libraries
Understanding the Cryptography Library
Understanding the Cryptosteganography Library
Image Cryptography
File Cryptography Using Fernet
Image Cryptography Using Fernet
AES and Block Modes of Operations
Exploring a Simple ECB Mode Example
Exploring a Simple CBC Mode Example
Applying the Examples
Steganography
Storing a Message Inside an Image
Storing a Binary File Inside an Image
Working with large images
Summary
Chapter 7 Message Integrity
Message Authentication Codes
Hash-based Message Authentication Code
Using HMAC to Sign Message
Message Digest with SHA
Binary Digests
NIST Compliance
CBC-MAC
Birthday Attacks
Crafting Forgeries
The Length Extension Attack
Setting Up a Secure Channel
Communication Channels
Sending Secure Messages Over IP Networks
Create a Server Socket
Create a Client Socket
Create a Threaded Server with TCP
Adding Symmetric Encryption
Concatenate Message and MAC
Summary
References
Chapter 8 Cryptographic Applications and PKI
The Public-Key Transformation
Exploring the Basics of RSA
Generating RSA Certificates
Constructing Simple Text Encryption and Decryption with RSA Certificates
Constructing BLOB Encryption and Decryption with RSA Certificates
The El-Gamal Cryptosystem
Elliptic Curve Cryptography
Generating ECC Keys
Key Lengths and Curves
Diffie-Hellman Key Exchange
Summary
Chapter 9 Mastering Cryptography Using Python
Constructing a Plaintext Communications Application
Creating a Server
Creating the Client
Creating the Helper File
Execution
Installing and Testing Wireshark
Implementing PKI in the Application Using RSA Certificates
Modifying the Server
Modifying the Client
Modifying the Helper File
Execution
Implementing Diffie-Hellman Key Exchange
Modifying the Server File
Modifying the Client File
Modifying the Helper File
Creating the Diffie-Hellman Class File
Execution
Wrapping Up
Index
EULA
