Implementing Cryptography Using Python

ISBN-13: 9781119612209 / Angielski / Miękka / 2020 / 304 str.

Shannon Bray

Spis treści

Introduction xviiChapter 1 Introduction to Cryptography and Python 1Exploring Algorithms 2Why Use Python? 2Downloading and Installing Python 3Installing on Ubuntu 4Installing on macOS 4Installing on Windows 4Installing on a Chromebook 4Installing Additional Packages 5Installing Pip, NumPy, and Matplotlib 6Installing the Cryptography Package 7Installing Additional Packages 8Testing Your Install 9Diving into Python Basics 9Using Variables 10Using Strings 11Introducing Operators 11Understanding Arithmetic Operators 11Understanding Comparison Operators 13Understanding Logical Operators 13Understanding Assignment Operators 14Understanding Bitwise Operators 15Understanding Membership Operators 15Understanding Identity Operators 16Using Conditionals 16Using Loops 17for 17while 18continue 18break 18else 18Using Files 19Understanding Python Semantics 20Sequence Types 20Introducing Custom Functions 26Downloading Files Using Python 27Introducing Python Modules 28Creating a Reverse Cipher 29Summary 30Chapter 2 Cryptographic Protocols and Perfect Secrecy 31The Study of Cryptology 32Understanding Cryptography 32Cryptography's Famous Family: Alice and Bob 33Diffie-Hellman 34Data Origin Authentication 34Entity Authentication 35Symmetric Algorithms 36Asymmetric Algorithms 36The Needham-Schroeder Protocols 36The Otway-Rees Protocol 38Kerberos 39Multiple-Domain Kerberos 40X.509 41Formal Validation of Cryptographic Protocols 46Configuring Your First Cryptographic Library 47Understanding Cryptanalysis 47Brute-Force Attacks 47Side-Channel Attacks 48Social Engineering 48Analytical Attacks 48Frequency Analysis 48Attack Models 49Shannon's Theorem 50One-Time Pad 51XOR, AND, and OR 51One-Time Pad Function 56One-Way Hashes 58Cryptographic One-Way Hashes 59Message Authentication Codes 60Perfect Forward Secrecy 60Published and Proprietary Encryption Algorithms 61Summary 62References 62Chapter 3 Classical Cryptography 65Password Best Practices 66Password Storage 66Hashing Passwords 67Salting Passwords 67Stretching Passwords 68Password Tools 68Obfuscating Data 69ASCII Encoding 70Base64 Encoding Text 70Binary Data 72Decoding 72Historical Ciphers 72Scytale of Sparta 73Substitution Ciphers 73Caesar Cipher 74ROT-13 76Atbash Cipher 77Vigenère Cipher 77Playfair 79Hill 2x2 83Column Transposition 87Affine Cipher 90Summary 93Chapter 4 Cryptographic Math and Frequency Analysis 95Modular Arithmetic and the Greatest Common Devisor 96Prime Numbers 97Prime Number Theorem 98School Primality Test 98Fermat's Little Theorem 100Miller-Rabin Primality Test 100Generate Large Prime Numbers 104Basic Group Theory 106Orders of Elements 107Modular Inverses 109Fermat's Little Theorem to Find the Inverse 110Extending the GCD 111Euler's Theorem 111Pseudorandomness 115Breaking C's rand() Function 116Solving Systems of Linear Equations 117Frequency Analysis 120Cryptanalysis with Python 123Using an Online Word List 125Determining the Frequency 126Breaking the Vigenère Cipher 129Summary 138Chapter 5 Stream Ciphers and Block Ciphers 139Convert between Hexdigest and Plaintext 140Use Stream Ciphers 141ARC4 147Vernam Cipher 148Salsa20 Cipher 149ChaCha Cipher 151Use Block Ciphers 156Block Modes of Operations 158ECB Mode 158CBC Mode 159CFB Mode 160OFB Mode 162CTR Mode 163Tricks with Stream Modes 164DIY Block Cipher Using Feistel Networks 165Advanced Encryption Standard (AES) 167Using AES with Python 167File Encryption Using AES 169File Decryption Using AES 169Summary 169Chapter 6 Using Cryptography with Images 171Simple Image Cryptography 171Images and Cryptography Libraries 174Understanding the Cryptography Library 174Understanding the Cryptosteganography Library 175Image Cryptography 175File Cryptography Using Fernet 176Image Cryptography Using Fernet 179AES and Block Modes of Operations 180Exploring a Simple ECB Mode Example 181Exploring a Simple CBC Mode Example 185Applying the Examples 186Steganography 187Storing a Message Inside an Image 188Storing a Binary File Inside an Image 192Working with large images 195Summary 197Chapter 7 Message Integrity 199Message Authentication Codes 200Hash-based Message Authentication Code 201Using HMAC to Sign Message 202Message Digest with SHA 203Binary Digests 204NIST Compliance 205CBC-MAC 206Birthday Attacks 207Crafting Forgeries 209The Length Extension Attack 209Setting Up a Secure Channel 210Communication Channels 211Sending Secure Messages over IP Networks 212Create a Server Socket 212Create a Client Socket 213Create a Threaded Server with TCP 214Adding Symmetric Encryption 215Concatenate Message and MAC 218Summary 221References 222Chapter 8 Cryptographic Applications and PKI 223The Public-Key Transformation 224Exploring the Basics of RSA 226Generating RSA Certificates 229Constructing Simple Text Encryption and Decryption with RSA Certificates 231Constructing BLOB Encryption andDecryption with RSA Certificates 232The El-Gamal Cryptosystem 235Elliptic Curve Cryptography 238Generating ECC Keys 240Key Lengths and Curves 241Diffie-Hellman Key Exchange 242Summary 245Chapter 9 Mastering Cryptography Using Python 247Constructing a Plaintext Communications Application 248Creating a Server 248Creating the Client 250Creating the Helper File 251Execution 252Installing and Testing Wireshark 253Implementing PKI in the Application Using RSA Certificates 255Modifying the Server 256Modifying the Client 257Modifying the Helper File 258Execution 259Implementing Diffie-Hellman Key Exchange 261Modifying the Server File 262Modifying the Client File 264Modifying the Helper File 266Creating the Diffie-Hellman Class File 270Execution 275Wrapping Up 276Index 277

O autorze

SHANNON W. BRAY CASP, Security +, CISM is the Virtual CISO at Secured Systems providing clients guidance on establishing and maintaining information security plans, policies, procedures, standards, and guidelines using accepted frameworks. He has worked in this roles and others in corporations and federal agencies. Shannon has an MS in Cybersecurity from the University of Delaware. Prior to transitioning to cybersecurity, he was a well known IT expert with several successful books about Microsoft SharePoint.