Crypto Talk

• Goal of Talk
  • What different primates are and what they are for
  • Not for building crypto - don't do that
• Purpose of Crypto
  • Privacy
  • Validation
  • Authenticity
• History
  • Substitution cipher → freq analysis
  • Vigener Cipher → freq analysis again
• Symmetric Cipher
  • Claude Shannon and perfect security
  • XOR OTP example
• Problems with OTP/sym.
  • key must be exchanged
    • PRG
    • Still must be OTP
  • Repeat attack
  • Substitution attack
• Hashing
  • What is a hash
  • MAC
  • Pigeon hole and collision resistance
• Block Ciphers
  • AES
  • Behaves as PRG, Hash and cipher
  • CBC vs CTR
  • Nonce
• Putting it all together
  • AES with MAC
• Asymmetric
  • Diffe-Hellman - won't cover, but they got there first
  • Key exchange
  • RSA
  • Elliptic