[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: Small subgroups and ISAKMP/Oakley



I agree with you that implementors should not have to become number theorists.
Given the rather protracted development time for this family of standards I think it is
advisable to nail down as much as possible in Oakley.  No doubt, other key management mechanisms
will be developed in the future to fit under the ISAKMP framework.  In other words, I think there is a lot of wisdom to restricting the degrees of freedom offered in Oakley.  Using j=2 is a nice conservative choice and any potential loss of efficiency by not allowing a larger j (i.e. smaller q) is negligible at this point.

-John Kennedy


>>> Hilarie Orman <ho@earth.hpc.org> 04/17/97 07:42AM >>>
> On the Sophie-Germaine/j=2 thing:
> 
> Is there some reason you think having j>2 is a problem?  Using a 160-bit q is not necessarily a bad thing.
 
One reason that it is bad is that it may force implementors to become
number theorists.  While in the greater scheme of things, this would be
a positive development, in the small it is merely quixotic.

Is there some reason that j=2 is an unreasonable restriction?  The
only reason I can see for non-Sophie-Germaineness* is that it might be
possible for one party to propose a new group of a particular type and
for the recipient to verify its subgroup structure quickly (a few
minutes).

Hilarie

Why not simply Germaine primes?  No one says Emma-Noetherian rings.
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               !