SOI QUESTION: 3.4 Preferred ID for responder

["Theodore Ts'o" <tytso@mit.edu>]

Please discuss and answer this question:

3.4 Preferred ID for responder

3.4.A) In JFK and IKEv2, the initiator can include a payload is an 
indication to the responder as to what identity (and corresponding key 
material) the responder should use to authenticate to the initiator. In 
JFKr and IKEv2, this value is encrypted in message 3; in JFKi, it is sent 
in the clear in message 1, thereby allowing a passive attack on the 
responder's likely identity. Is it important to encrypt this identity?

Implications from the scenarios:

[none]