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Re: HTTP2 Expression of Interest

From: Mike Belshe <mike@belshe.com>
Date: Tue, 17 Jul 2012 21:16:57 -0700
Message-ID: <CABaLYCtoWHAz_Vpp4bmkEB7LB2RuAjM072wXzvjQ8RXHv70avQ@mail.gmail.com>
To: Phillip Hallam-Baker <hallam@gmail.com>
Cc: Martin J. Dürst <duerst@it.aoyama.ac.jp>, Doug Beaver <doug@fb.com>, Willy Tarreau <w@1wt.eu>, "ietf-http-wg@w3.org" <ietf-http-wg@w3.org>
On Tue, Jul 17, 2012 at 8:59 PM, Phillip Hallam-Baker <hallam@gmail.com>wrote:

> RC4 is cheap but SHA2 is not.
>
> Encryption without authentication is worthless. The principal security
> objective in TLS is to provide integrity, not confidentiality. If you
> lose integrity you are going to lose confidentiality even with 128 bit
> encryption.
>
>
> RC4 is a stream cipher. It is fast but thats about all that can be
> said in its favor. If I care about confidentiality I am not going to
> want a stream cipher.
>

I believe RC4 is excellent for almost all cases.  It is certainly used on
millions of sites today just fine.

If the alternative is no security (e.g. arguing for no TLS), we can
probably agree that RC4 is more secure than that! :-)  Obviously, if you
want even stronger security, you can opt in to using other crypto
algorithms - those are configurable through TLS today.  No problem.
Requiring TLS with HTTP/2.0 would not need to require an expensive
symmetric crypto algorithm.

Mike





>
>
> On Tue, Jul 17, 2012 at 11:44 PM, Mike Belshe <mike@belshe.com> wrote:
> >
> >
> > On Tue, Jul 17, 2012 at 7:35 PM, "Martin J. Dürst" <
> duerst@it.aoyama.ac.jp>
> > wrote:
> >>
> >> Hello Doug, everybody,
> >>
> >>
> >> On 2012/07/18 7:11, Doug Beaver wrote:
> >>
> >>>    * Symmetric crypto costs are not much higher; I think Akamai quoted
> >>> 10-20%
> >>>      in their response. I think the costs aren't a big deal for major
> >>> sites;
> >>
> >>
> >> Just a quick question: I think if we could shave off 10-20% of the
> >> bandwidth with some new technique, we'd all go for it.
> >
> >
> > Symmetric crypto (RC4) is super super cheap - a couple of XORs -
> definitely
> > not 10-20% of CPU.  I'd like to see that measured again before taking
> action
> > upon it.  Obviously, if you use expensive crypto (presumably because you
> > want it), some algorithms take more CPU
> >
> > mike
> >
> >>
> >>
> >> So why are we okay with 10-20% more processing costs for everybody, but
> >> not with 10-20% more bandwidth? What's different between processing
> costs
> >> and bandwidth?
> >>
> >> Regards,   Martin.
> >>
> >
>
>
>
> --
> Website: http://hallambaker.com/
>
Received on Wednesday, 18 July 2012 04:17:25 GMT

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