Re: [IPsec] New draft on IKE Diffie-Hellman checks

["Dan Harkins" <[e-mail]>]

  I made a mistake below. Thanks to Dan Brown for pointing it out.

On Tue, December 11, 2012 10:06 am, Dan Harkins wrote:
[snip]
>   - I think it should be mentioned that elliptic curve groups
>      have a co-factor, h, and if h > 1 that a further check is
>      also required, namely, if the x- and y-coordinates define
>      a point Q then ensure that:
>
>            hQ = point-at-infinity
>
>      Add this check to both 2.3 and 2.4. Of course if h=1 then this
>      check can be skipped.

  The check should be hQ != point-at-infinity. An equivalent check
could be nQ = point-at-infinity where n is the order of the group
formed by the generator, G.

  regards,

  Dan.