Most of this lecture were repetition from Cryptology1, but there were some new interesting things (The repetition was easy to follow and well written though)

• More in detail on types of hashes: insecure and secure hash algorithms. Secure hash algorithms can be keyed and non-keyed.
  
• The difficulty of managing cryptographic keys, the numbers required, Trusted third party, Certificate Authorities etc.
  
• Adding hash of encrypted message or hashing clear text and then encrypting it all?
  
• MAC codes: Message authentication using secret (symmetric or asymmetric)
  
• Nonce's: time-stamp, sequence number, IV, salt
  
• Identification vs authentication definitions (different than previous definitions: Identification related to persons and authentication related to cryptology)
  
• AH and ESP in IPsec: Authentication Header and Encapsulating Security Payload. Transport mode and tunnel mode.