Phase 1 - Main Mode (2) (simplified)

• Second message pair's aim: Establish a shared secret and derive IKE session keys

  • Uses Diffie-Hellman with the group agreed upon with the first message pair.
  • Two of the derived keys will be used, with the negotiated encryption algorithm and hash function, to protect the following IKE messages.
  • The nonces protect against replay by taking part in the shared secret computation.