On Thursday 19 May 2005 06:10, Nelson Bolyard wrote:
> Ian G wrote:
> > On Wednesday 18 May 2005 07:24, Nelson B wrote:
> >>Ian G wrote:
> >>>In practice, sites see HTTPS as a cost, and a barrier.  It doesn't
> >>>provide any protection that they *need* although this might be
> >>>less true in the future and for big sites.
> >>
> >>So, you're saying they don't need encryption, they don't need
> >>authentication, they don't need validation, and (I gather)
> >
> > Actually, the sites need authentication and validation,
> > but of their users, and this is provided by passwords
> > and user names, primarily.
> >
> > [...] the passwords are protected from eavesdropping by SSL.
>
> So, you're saying they need password protection from eavesdropping,
> but not encryption, authentication or validation?

Yes, but be careful of that nutshell.  That's close to
what they *need* but they could also desire other
things.  So that makes it a requirement.  Encryption
is something that might or might not meet that
requirement.

They need password protection from eavesdropping,
and this is experience that seems to be concurred
with by SSH and bugzilla.mozilla.org for example.
Although many sites do in fact do financial transaction
using passwords without password protection, I think
myself that's a risk they only take because protection
is so expensive.  (I am facing this case at the moment,
and the expense of properly protecting passwords
within the web coding scenario I am dealing with is
just too high to be acceptable, I may end up having
to port my own crypto code into the PHP web server
just to get it done.  Which is fun but hardly economically
sensible.)

As a requirement, it does not strongly indicate
encryption, as simple protections schemes for mailing
lists are in wide usage and work quite well by simply
mailing out the password or a check over email.  A
higher degree of separation through alternate means
is now popular in online banking circles where SMS
is used.

So one could probably suggest that encryption
would be sufficient to meet the requirement for
protection, without authentication and validation,
for most web password purposes.  Also, one could
do it with challenge-response schemes, SRP and
the like.  (I seem to recall there are some schemes
like this built in to HTTP but I'm unaware of what
they are.)

This is not to say that sites wouldn't use authentication
and validation as well as encryption if they were offered
and were cheap, but rather to challenge the hypothesis
that encryption without authentication and validation is
"unworkable" or "meaningless."

( I won't put this in concrete terms because it will
likely be misconstrued it as a 'position'.  This is a
conceptual discussion as to why sites do not use
more HTTPS, so we need to get away from the
minutae and concentrate on the requirements, and
the costs and benefits of various technologies that
claim to meet those requirements, in order to decide
what is facing merchants and other web sites. )

iang
-- 
Advances in Financial Cryptography:
   https://www.financialcryptography.com/mt/archives/000458.html
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