1440  Encryption Principles and Crypto Basics

1440.1 Overview

This comprehensive guide covers cryptographic fundamentals for IoT security. The content has been organized into focused chapters for easier learning and reference.

TipIn Plain English

Encryption scrambles your data so only authorized people can read it. Even if someone intercepts your message, they see gibberish without the key. It’s the foundation of all IoT security.

Everyday Analogy: Encryption is like a lockbox. Anyone can see the box (encrypted data traveling over the network), but only someone with the key can open it and read what’s inside (decrypt the data).

Why it matters: Without encryption, your smart doorbell video, fitness tracker heart rate, voice commands, and door unlock signals travel in plain text - anyone on the network can see, record, and replay them. With encryption, attackers see only scrambled data they can’t decrypt.

1440.2 Learning Objectives

By completing this chapter series, you will be able to:

  • Understand Cryptographic Fundamentals: Explain the purpose and mechanics of encryption for IoT security
  • Compare Algorithm Types: Distinguish between symmetric (AES) and asymmetric (RSA, ECC) encryption and their use cases
  • Apply Hashing Functions: Use cryptographic hashes (SHA-256) for data integrity and password storage
  • Implement Key Management: Design secure key generation, distribution, and rotation strategies
  • Select IoT-Appropriate Crypto: Choose lightweight cryptographic solutions for resource-constrained devices
  • Understand TLS/DTLS: Explain how transport security protocols protect IoT communications

1440.3 Chapter Guide

This topic is divided into focused chapters. Start with the fundamentals or jump to specific topics:

1440.3.1 Core Concepts

Chapter Focus Difficulty
Symmetric Encryption AES, block ciphers, modes of operation Intermediate
Asymmetric Encryption RSA, Diffie-Hellman, digital signatures Intermediate
Elliptic Curve Cryptography ECC for IoT, Curve25519, Ed25519 Advanced
Hash Functions SHA-256, HMAC, data integrity Intermediate

1440.3.2 Applied Security

Chapter Focus Difficulty
TLS/DTLS Transport Security Secure connections, certificates, handshakes Intermediate
Key Management Key lifecycle, storage, rotation Intermediate

1440.3.3 Hands-On Learning

Chapter Focus Difficulty
Interactive Tools Calculators, comparisons, decision aids Beginner
Encryption Labs Wokwi ESP32 simulations, exercises Intermediate
Cipher Challenge Game Interactive puzzles, knowledge testing Beginner

1440.4 Quick Reference

1440.4.1 Encryption Type Selection

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flowchart TD
    Start(["What's your need?"]) --> Q1{"Encrypting bulk data?"}

    Q1 -->|"Yes"| Sym["Use Symmetric (AES)"]
    Q1 -->|"No"| Q2{"Need key exchange?"}

    Q2 -->|"Yes"| Asym["Use Asymmetric (ECC/RSA)"]
    Q2 -->|"No"| Q3{"Need signatures?"}

    Q3 -->|"Yes"| Sign["Use Ed25519/ECDSA"]
    Q3 -->|"No"| Hash["Use SHA-256"]

    style Start fill:#2C3E50,stroke:#16A085,color:#fff
    style Sym fill:#16A085,stroke:#2C3E50,color:#fff
    style Asym fill:#E67E22,stroke:#2C3E50,color:#fff
    style Sign fill:#E67E22,stroke:#2C3E50,color:#fff
    style Hash fill:#7F8C8D,stroke:#2C3E50,color:#fff

1440.4.2 IoT Encryption Recommendations

Use Case Symmetric Asymmetric Hash
Sensor data encryption AES-128-GCM - -
Key exchange - ECC-256 -
Firmware signing - Ed25519 SHA-256
Password storage - - Argon2
TLS connections AES-128-GCM ECDHE SHA-256

1440.4.3 Key Size Comparison

Security Level AES RSA ECC
128-bit 128 bits 3072 bits 256 bits
192-bit 192 bits 7680 bits 384 bits
256-bit 256 bits 15360 bits 512 bits

Takeaway: ECC provides RSA-equivalent security with 10x smaller keys - ideal for IoT.

1440.5 Prerequisites

Before diving into these chapters, you should be familiar with:

1440.7 Getting Started

New to cryptography? Start with:

  1. Interactive Tools - Build intuition with calculators
  2. Symmetric Encryption - Learn AES fundamentals
  3. Cipher Challenge Game - Test your knowledge

Building IoT devices? Focus on:

  1. Symmetric Encryption - AES-GCM for data
  2. ECC - Small keys for constrained devices
  3. TLS/DTLS - Secure connections
  4. Key Management - Proper key handling

Hands-on learner? Jump to:

  1. Encryption Labs - ESP32 simulations
  2. Cipher Challenge Game - Interactive puzzles

1440.8 Summary

Encryption is the foundation of IoT security, protecting data confidentiality, integrity, and authenticity. This chapter series covers:

  • Symmetric encryption (AES) for fast, efficient data protection
  • Asymmetric encryption (RSA, ECC) for key exchange and signatures
  • Hash functions (SHA-256) for integrity verification
  • TLS/DTLS for secure transport connections
  • Key management for the complete security lifecycle

Explore the focused chapters above to master each topic.