Cryptography by Hand

December 30 2024 Home ·

• Preface
  • Disclaimer
• Encryption with the One-Time Pad
  • What a One-Time Pad Looks Like
  • Creating Keys
  • Encrypting Messages
  • Decrypting Messages
  • How the One-Time Pad Works
  • One-Time Pad Guarantees
  • Requirements for Perfect Secrecy
  • One-Time Pad Weaknesses
  • Example Program
• A Variation of the CT-37c Translation Table
• Message Authentication Codes
  • Introduction to Message Authentication Codes
    • How MACs Work
    • MACs Cannot Guarantee Authenticity
    • When to Use MACs
  • Simple Message Authentication Codes
    • Simple Message Authentication Keys
    • Creating Keys
    • Signing Encrypted Messages
    • Verifying Encrypted Messages
    • Why These MACs Work
  • More Sophisticated Message Authentication Codes
    • Creating Keys
      • Choosing Key Security Parameters
      • Generating Your Key's Random Numbers
        • Dice Notation
        • Generating Random Numbers for Different Security Parameters
      • An Example MAC Key
      • Making MAC Keys Infinitely Reusable
    • Signing Encrypted Messages
    • Verifying Received Messages
    • Why These MACs Work
    • Example Programs
      • Python
      • dc(1)
• Steganography
  • Why Hide Messages?
  • How to Hide Messages
    • Word Counts in Prose
    • Word Counts in Poetry
    • Strokes in Chinese Characters
    • Counts in Visual Art
    • Math Questions and Puzzles
    • Quotations from Shared Texts