Background

• Keys lifetimes and roles

  • Keys with a long lifetime (long-term keys) are generally used for peer authentication only.
  • The keys used for data protection (encryption and authentication) generally have a short lifetime and are called session keys because their lifetime is roughly the same as the session's lifetime.

• Perfect Forward Secrecy (PFS)

  • Even if an attacker discovers long-term secret(s), he will not be able to recover the session keys (past and future).
  • Provided when long-term secrets are only used for authentication and do not take part in session keys generation.

• Identity Protection

  • No identity is transmitted in the clear, so a spy can't know who the communicating peers are.