[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: Comments on CRACK
Scott,
"Scott G. Kelly" wrote:
> Stephane Beaulieu wrote:
> > What would those be?
> >
> > I've heard...
> >
> > 1 - It encourages the use of weak pre-shared keys. - Perhaps, but this can
> > easily be fixed in XAUTH. I would still like to get a concensus on this.
>
> This "easy" fix requires deployment of client certificates.
Deployment of client certificates together with hardware tokens (preferably FIPS
140-1 level 4 certified) is the best fix. The easy secure fix is hybrid.
> > 2 - It's too complicated to be secure... Please !
>
> Prove to me that it's secure. Better review your predicate logic
> first...
Let's start from the beginning, all the suggested protocols are based on IKE, so
we can start with a proof of security for IKE. Then we can try to give a proof in
the same level for the other suggestions.
> > 3 - Too much known plain text. - All three proposals (XAUTH, CRACK, and ULA
> > have know plain text.
>
> None have the copious amounts of ASCII TEXT that xauth does. Some known
> plaintext may be unavoidable, but xauth has a ridiculous amount.
Know plain text is non-issue (BTW actually the largest amount of known plain text
is with certificate, when the whole public certificate chain is being passed).
Regards,
Moshe
begin:vcard
n:Litvin;Moshe
tel;fax:+972 3 5759256
tel;work:+972 3 7534601
x-mozilla-html:TRUE
org:Check Point Software Technologies Ltd.
adr:;;;;;;
version:2.1
email;internet:moshe@CheckPoint.com
fn:Moshe Litvin
end:vcard
References: