Materials

Use the raw slides (pdf) before lecture to take notes.

Summary

• Review: Security against computationally bounded adversaries (run in polynomial time)
• Review: success of the adversary must be small (how small?)
• Is IND enough ?
• INDCPA game allows an adversary to ask for encryptions of any messages they want.
  • Why is this more secure?
• Problems with symmetric key encryption
• Introducing the public key model
• IND-CPA for PKC (slightly different than IND-CPA for symmetric, why?)
• How to build PKC encryption
  • Basic number theory
  • Euler’s totient function
• Textbook RSA (is insecure, why?)
• OAEP, Examples
• Introducing the age-old problem of authenticity