Re: Draft multi6 minutes

[Tim Shepard <shep@alum.mit.edu>]

> Tim Shepherd (TS): Any reaction from IPsec or SAAG on this?

My name is spelled Shepard.

> TS: I am wondering if hash based address approach, seems to give 
> little security but not much. can choose to give work factor of 1,
> attacker 2^59 or give them or take 2^72 to give them 2^91 (or another
> choice) and the constraints are to fit the hash into the space. don't
> want to make the /64 boundary rigid. somebody might want to be routing
> longer prefixes. so hash is even smaller. wondering if need to go to
> 2^32 work factor to make this secure enough, set the puzzle, might as
> well go ahead and do PK work. The high level question is, what are we
> trying to secure, and is it secure enough?
> 

I was trying to point out that the HBA scheme seems to allow you these
three choices (if I understand it correctly):

user work factor       attacker work factor
----------------       --------------------
  1                             2^59
 2^16                           2^75
 2^32                           2^91


and it's not clear that any of those are useful.  

If security is not needed, then perhaps we don't even need to use the
HBA scheme.  If security is needed, then perhaps this scheme isn't
much better than using some public key cryptography.

> TS: Key mgt. Even Christian mentioned this, can use PK in ways which
> dont need mgt, purpose built keys, draft written a while ago. 

I do remember saying that, but:

> TS: Purpose built keys, guarantees person start talking to will be
> person finish talking to. Other examples check neighbour discovery 

I do not remember saying that.  I thinks someone else got up and said
that at the same mic I had used, and it might have been Eliot
Lear. (But I'm not sure.)


			-Tim Shepard
			 shep@alum.mit.edu