Cryptography by Hand

May 9 2023 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
  • How MACs Work
  • MACs Cannot Guarantee Authenticity
  • When to Use MACs
  • 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 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