questions on RFC2631 and DH key agreement

[Ali, Saqib]

http://www.xml-dev.com/blog/index.php?action=viewtopic&id=196

On 2/1/08,  =JeffH  <Jeff.Hodges at kingsmountain.com> wrote:
>
> So AFAICT from perusal of RFC2631 "Diffie-Hellman Key Agreement Method" and
> RFC2630 CMS, when one executes a simple DH static profile between two parties,
> the only things that really need to go over the wire are each party's public
> keys (ya and yb) if { p, q, g, j } are known to both parties. And thus,
> "Generation of Keying Material" is done by each party separately, using the
> value of ZZ that each independently calculates, yes?  Thus keying material
> doesn't cross the wire and risk exposure (among various things).
>
> So if p, q, g are not static, then a simplistic, nominally valid, DH profile
> would be to..
>
>
>       a                                         b
>   ----------                               ----------
>
>   g, p, ya ------------------------------------>
>
>
>       <--------------------------------------- yb
>
>
>  [calculates ZZ]                         [calculates ZZ]
>  [calculates keying material]            [calculates keying material]
>       .                                         .
>       .                                         .
>       .                                         .
>
>
>
> ..yes?
>
>
> Other than for b perhaps wanting to verify the correctness of { p, q, g, j }
> ("group parameter validation"), is there any reason to send q ?
>
>
>
> thanks,
>
> =JeffH
>
>

---------------------------------------------------------------------
The Cryptography Mailing List
Unsubscribe by sending "unsubscribe cryptography" to majordomo at metzdowd.com