Re: [hybi] AES-128-CTR not much safer, but not fast either

[Adam Barth <[e-mail]>]

On Sun, Jan 9, 2011 at 10:58 PM, Willy Tarreau <[e-mail]> wrote:
> On Sun, Jan 09, 2011 at 10:44:19PM -0800, Adam Barth wrote:
>> Or we could just use AES-128-CTR like everyone else in the known
>> universe and not worry about whether we've shaved exactly the right
>> number of hairs off our home-brew pseudo crypto.
>
> Adam, I just explained that AES-128-CTR as you proposed it does not
> address the points that were raised which made it appear here.
>
> In fact the real problem we really want to solve is make the CR/LF
> bytes disappear from the stream. Those bytes are still present with
> AES-128-CTR.

Fortunately, we don't need to make the CR/LF bytes disappear from the
stream.  What we need to do is prevent the attacker from choosing a
string that can be used to attack an intermediary.  Using AES-128-CTR
makes it so the attacker is forced to choose a pseudo-random sequence
of bytes.  I claim that it is infeasible to attack an intermediary in
this way using a pseudo-random sequence of bytes.

Kind regards,
Adam