HCR for key negotiation

[Watson Ladd]

First some background:
The NSA's Suit B uses a key negotiation mutual authentication method MQV.  This method was found to be insecure, and so HMQV was created. HMQV uses a signature protocol called HCR twice in one exchange to generate a key. HCR can prove identy of one endpoint and negotiate a key in a two message exchange with great efficiency for both sides.
In Tor the current key generation method is quite expensive. Would it be possible to change to HCR to improve efficency?

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"Those who would give up Essential Liberty to purchase a little Temporary Safety deserve neither  Liberty nor Safety."
-- Benjamin Franklin