[hiprg] Adding Identity privacy to HIP DEX

[Robert Moskowitz <[e-mail]>]

I faded early this evening and woke up in the middle of the night (hey, 
I am in Stockholm right now, it is 2am) with perhaps a wild idea that 
may make some sense.

I forfeited Identity privacy and PFS in DEX with moving the HI to ECDH 
and that ECDH exchange as the extent of the public key crypto in DEX.

Here is my thought.  The Initiator has TWO ECDH key pairs.  One is the 
HI, the other is an identity privacy key (IPK?).  I2 uses the IPK on the 
'outside' with the HI encrypted for an 'inner' ECDH protected exchange.  
The responders HI is still exposed.  It is ASSUMED that this is 
acceptable and that the Initiator has some mechanism to validate this HI 
to avoid a DH MITM.

I don't know if this is worth the effort to flesh out.  I have lots of 
other work to do on HIP-bis, HIP-DEX, core, and some Verizon projects.  
So I am asking here if others see Identity privacy as important enough 
to persue it?