- o Merge the KE1 and KE2 payloads into one KE payload that has
- the `signature' field. Provide it only if the perty is
- required to do authentication.
- o Add MUTUAL_AUTH flag to indicate that the party must perform
- authentication (to sign with their private key). Initiator
- may set it to indicate that it can authenticate but responder
- MAY require for the initiator to do authentication by setting
- the flag at the KE Start Payload reply phase. The responder
- performs authentication always as now as well.