Re: IKEv2 security consideration over-statement

[Paul Koning <pkoning@equallogic.com>]

>>>>> "PaulH" == Paul Hoffman </ VPNC <paul.hoffman@vpnc.org>> writes:

 PaulH> The sentence "Diffie-Hellman group number two, when used with a
 PaulH> strong random number generator and an exponent no less than 200
 PaulH> bits, is sufficient for use with 3DES" is probably not
 PaulH> true. Group 2 (1024 bits) is probably equivalent to about 80
 PaulH> bits of symmetric strength, not 112. A better wording for this
 PaulH> sentence is "Diffie-Hellman group number two, when used with a
 PaulH> strong random number generator and an exponent no less than 200
 PaulH> bits, is common for use with 3DES". That is, most VPN systems
 PaulH> only need 80ish bits of symmetric strength.

Sounds reasonable.  That suggests that a VPN application where this is
true might also find it sensible to use group 2 with AES, even though
in both cases the "net" security is somewhat less than the data cipher
keysize.

 PaulH> The sentence "Groups three through five provide greater
 PaulH> security" is misleading....
 PaulH> It is better to change this to simply say "Group
 PaulH> five provides greater security than group two."

Yes, I agree that that's a necessary change.

     paul