RE: IPS security draft: SRP groups (resend)

[vince_cavanna@agilent.com]

Hi David,
Sounds good, but I don't understand the motivation to use any primes other than those from IKE when we know those primes are certifiable and that a generator suitable for SRP can be easily and deterministically determined. Is there value in giving the user multiple choices for primes of a given size?
Vince 

|-----Original Message-----
|From: Black_David@emc.com [mailto:Black_David@emc.com]
|Sent: Monday, July 15, 2002 4:25 PM
|To: vince_cavanna@agilent.com; ips@ece.cmu.edu
|Subject: RE: IPS security draft: SRP groups (resend)
|
|
|Vince,
|
|> If we cannot prove the primality of our chosen moduli I 
|> thought why not use moduli, such as the well known groups 
|> from RFC 2412, whose primality has been proven. Tom Wu told 
|> me that would not be a problem provided we found generators 
|> other than 2 (the generator that is given in RFC 2412), 
|> because 2 in not useful (for these moduli) in SRP (I don't 
|> know why such is the case).
|
|Tom's already posed the required generators for the IKE groups
|to the list.  In addition, Tero Kivinen was in the process of
|proving the primality of Tom's SRP primes last night.  With
|luck we'll have a post to the list with pointers to the proof
|certificates soon.
|
|Thanks,
|--David
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|David L. Black, Senior Technologist
|EMC Corporation, 42 South St., Hopkinton, MA  01748
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